Footprints/Mounting Standards on Red Dot Sights

Introduction

With every passing year, more red dot sights are available on the market. There have never been as many optics manufacturers as there are now, which means that there have never been as many different optical devices as there are now.

Red Dot Sights
Red Dot Sights

Red dot sights have been steadily gaining in popularity – for this reason, they can be found in the offer of most manufacturers of optics around the world. Even companies such as Kahles and Leica, who haven’t manufactured red dot sights before, have recently launched their own versions.

In this article, the most common footprints/mounting standards used on red dot sights are listed. Each standard is described and an image of it is added. At the end of each section, red dot sights that use the footprint discussed are listed.

Docter/Noblex standard

This is one of the most widely used footprints in the field of red dot sights. It has two holes for screws and four sockets in which the pins on the mount/adapter fit, one in each corner. There is a wide range of mounts for this footprint on the market, which is one of the main reasons why it is used by so many manufacturers. Docter/Noblex standard is simple and reliable.

Red dot sights that share this footprint:

* These red dot sights have a Docter/Noblex footprint, but the adapter supplied with them has wider threaded sockets than adapters suited for a Docter/Noblex footprint. Consequently, thicker screws are enclosed. You can mount these red dots on an adapter designed specifically for the Docter/Noblex footprint, but you will need not be able to use the screws supplied with them – thinner screws are needed.

Docter, Noblex footprint
Docter, Noblex footprint on Noblex Sight II+
Docter, Noblex footprint
Docter, Noblex footprint on Leica Tempus
Docter/Noblex sight footprint
Docter/Noblex sight footprint

Note: distances between holes (sockets) are measured from and to the center of the hole (socket).

Important notes

Meopta Meosight III and Delta Optical MiniDot HD 25 use a footprint that is very similar to the one used by Docter. The four sockets, one in each corner, are in the exact same places. The holes for the screws, however, are not. This is why Meopta Meosight III and Delta Optical MiniDot HD 25 cannot be mounted on every adapter designed for the Docter/Noblex footprint. Several adapters are designed so that both Docter/Noblex footprint sights and Meopta Meosight III/Delta Optical MiniDot HD 25 can be mounted on them (see the images below).

Meopta Meosight III (above) and Docter Sight C (below) (source: Christian S.)
Meopta Meosight III (above) and Docter Sight C (below) (source: Christian S.)
Meopta Meosight III (above) and Docter Sight C (below) (source: Christian S.)
Meopta Meosight III (above) and Docter Sight C (below) (source: Christian S.)
An EAW adapter for Docter & Noblex footprint (left) and an adapter for Delta Optical MiniDot HD 25
An EAW adapter for Docter & Noblex footprint (left) and an adapter for Delta Optical MiniDot HD 25
Noblex Sight III (left) and Delta Optical MiniDot HD 25 (right)
Noblex Sight III (left) and Delta Optical MiniDot HD 25 (right)
Various adapters for the Docter/Noblex footprint (for different pistols) (source: Christian S.)
Various adapters for the Docter/Noblex footprint (for different pistols) (source: Christian S.)

Aimpoint Micro standard

Aimpoint is the first company to have used this standard on their Micro small tube sights. Today, other manufacturers of this type of sights use it as well. The surface of the footprint is slightly lifted in the middle – on each side of the lifted section, there are two holes for screws. The lifted section is cut in the middle – this is where the recoil stop fits.

Red dot sights that share this footprint:

Aimpoint Micro footprint
Aimpoint Micro footprint
Aimpoint Micro footprint
Aimpoint Micro footprint

Note: distances between holes (sockets) are measured from and to the center of the hole (socket).

Important notes

GPO Spectra uses a footprint that is identical to the one used by Aimpoint Micro. Even though it appears to be the same at first sight, there is a protruding part underneath the illumination knob. Because of it, the adapters designed for an Aimpoint Micro footprint do not fit into place at that side (check the picture below). GPO Spectra uses a unique adapter with narrow side sections.

GPO Spectra and its footprint (right) next to Aimpoint Micro H-2 and its footprint (left)
GPO Spectra and its footprint (right) next to Aimpoint Micro H-2 and its footprint (left)
An adapter designed for GPO Spectra's footprint (right) next to the adapter designed for Aimpoint Micro's footprint (left)
An adapter designed for GPO Spectra’s footprint (right) next to the adapter designed for Aimpoint Micro’s footprint (left)
An adapter designed for GPO Spectra's footprint
An adapter designed for GPO Spectra’s footprint
GPO Spectra footprint
GPO Spectra footprint

Hawke Endurance 1×25 and 1×30 red dot sights also use a footprint slightly different from the Aimpoint Micro one. The lifted section in the middle is wider, thus adapters designed for a Docter/Noblex footprint do not fit in place.

Hawke Endurance 1x30 red dot sight footprint
Hawke Endurance 1×30 red dot sight footprint
Hawke Endurance 1x30 does not fit on an EAW adapter designed for a Docter & Noblex footprint
Hawke Endurance 1×30 does not fit on an EAW adapter designed for a Docter & Noblex footprint

C-more standard

This is a standard found on C-more’s popular red dot sights, RTS and STS. Some other manufacturers also use it because of its simplicity and reliability. The footprint has two holes for screws and two sockets in which the pins on the mount/adapter fit.

Red dot sights that share this footprint:

C-more footprint
C-more footprint
C-more footprint
C-more footprint

Note: distances between holes (sockets) are measured from and to the center of the hole (socket).

Shield standard

Shield sights are incredibly compact, which is why Shield had to come up with a footprint of their own. It is designed similarly to the Noblex/Docter footprint (there are two holes for the screws and four sockets in which the notches on the mount/adapter fit, one in each corner). The sockets, however, are a little bit wider and closer one to another.

Red dot sights that share this footprint:

Shield footprint
Shield footprint
Docter, Noblex footprint (top) and Shield footprint (bottom)
Docter, Noblex footprint (top) and Shield footprint (bottom)
Shield sight footprint
Shield sight footprint

Note: distances between holes (sockets) are measured from and to the center of the hole (socket).

A modification of the Shield standard

Holosun 407K and Holosun 507K feature a modification of the Shield footprint. The differences are:

  • the two rear sockets are missing
  • the sockets in the front are shallower

For this reason, some pistols that are optic ready for Shield footprint need to be modified for the 407 and 507K. Namely, the two rear indexing lugs on the pistol have to be removed and the two front indexing lugs shortened in height. Hellcat and Walther PPS are examples of such pistols (some pistols, such as Sig Sauer P365XL, do not have to be modified).

Holosun 407K and 507K footprint
Holosun 407K and 507K footprint

 ‘Trijicon RMR’ standard

This footprint has two holes for screws and two sockets in which the pins on the mount/adapter fit – these are in the front, in each corner. Even though the sockets are in the front only, the footprint is somewhat reminiscent of the Docter/Noblex one. Note, however, that the sockets in the corners are farther apart on the Trijicon footprint and bigger in diameter.

Red dot sights that share this footprint:

Trijicon RMR footprint
Trijicon RMR footprint
Trijicon RMR footprint
Trijicon RMR footprint

Note: distances between holes (sockets) are measured from and to the center of the hole (socket).

There are many other, unique footprints on the market. Sig Sauer’s Romeo 1, for example, has a footprint suitable for mounting on certain Sig Sauer pistols – you will need a special adapter if you wish to mount it elsewhere. Steiner uses a different approach for their MRS – there are only two narrow notches in the front, while the holes for the screws are located at the rear of the sight, on both sides, left and right.

‘Trijicon MRO’ standard

There are four screw holes on the footprint, two in the front, two in the rear. The holes on the left are separated from the holes on the right with a lifted section in the middle.

Red dot sights that share this footprint:

  • Trijicon MRO
  • Trijicon MRO Patrol
Trijicon MRO footprint

A modification of the ‘Trijicon MRO’ footprint

Vector Optics Centurion 1×30 features a modification of the ‘Trijicon MRO’ footprint. The distances between the screw holes are the same, and so is the thread. The difference is in the lifted section. On Centurion, the middle part of the lifted section is cut out to create space for a recoil stop. For this reason, a mount designed for the Trijicon MRO footprint fits on the Centurion, while a mount designed for the Vector Optics Centurion (with a recoil stop) does not fit on the MRO (the middle part of the lifted section is not cut out).

Vector Optics Centurion 1x30 Footprint
Vector Optics Centurion 1×30 Footprint

Red dot sights that have a unique footprint

This red dot sight has a unique footprint that works similarly to a footprint designed for the Picatinny rail. The adapters suitable for it are slid into place and then fixed with the movable side section. A recoil stop helps keep the adapter in place.

Holosun 509T footprint
Holosun 509T footprint
Holosun 509T footprint
Holosun 509T footprint
Holosun 509T with an RMR adapter for its footprint
Holosun 509T with an RMR adapter for its footprint
  • Holosun Infinity models

The footprint of the Infinity models is flat, with three notches for recoil stoppers. The adapter is fixed in place with four screws.

Holosun Infinity footprint
Sig Sauer Romeo 1 Footprint
Sig Sauer Romeo 1 Footprint

All Steiner MRS red dot sights share the same footprint. The ‘Universal’ model, however, is supplied with an adapter which converts the footprint into the one designed for Docter/Noblex adapters.

Steiner MRS footprint
Steiner MRS footprint
Steiner MRS Universal's footprint
Steiner MRS Universal’s footprint
Steiner MRS Universal with the supplied adapter for the Docter & Noblex footprint
Steiner MRS Universal with the supplied adapter for the Docter & Noblex footprint
Steiner MRS with the supplied adapter, paired with a Picatinny adapter for the Docter & Noblex footprint
Steiner MRS with the supplied adapter, paired with a Picatinny adapter for the Docter & Noblex footprint
Holosun Paralow HS403 A footprint
Holosun Paralow HS403 A footprint
DI Optical RV2 footprint
DI Optical RV2 footprint

Even though this footprint looks identical to the one on DI Optical RV2, there are minimal differences between the two. The lifted sections with screw holes are narrower on RV2. Because of some other minimal deviations, the supplied adapters are not interchangeable between these two sights.

Vector Optics Nautilus 1×30 footprint
DI Optical RV 2 (left) and Vector Optics Nautilus 1x30 (right) with supplied adapters
DI Optical RV 2 (left) and Vector Optics Nautilus 1×30 (right) with supplied adapters
DI Optical RV 2 (left) and Vector Optics Nautilus 1x30 (right)
DI Optical RV 2 (left) and Vector Optics Nautilus 1×30 (right)
Aimpoint ACRO footprint
Aimpoint ACRO footprint
From left to right - Holosun 509 T adapter, Aimpoint ACRO adapter, Aimpoint ACRO, Holosun 509T
From left to right – Holosun 509 T adapter, Aimpoint ACRO adapter, Aimpoint ACRO, Holosun 509T
Holosun 509T Adapter (left) and Aimpoint ACRO adapter (right)
Holosun 509T Adapter (left) and Aimpoint ACRO adapter (right)
Aimpoint Acro footprint
Aimpoint Acro footprint

Note: distances between holes (sockets) are measured from and to the center of the hole (socket).

This article will be constantly updated in the future. With it, we wish to create a collection of useful data that will be of great help to users/potential buyers of red dot sights and those who are looking for a specific mount/adapter for their red dot sight. If you have a compact reflex or small tube sight that isn’t listed in this article, please be so kind as to send a picture of the sight and its footprint to andraz.gradisnik@optics-trade.comhelp us expand our database. We greatly appreciate everyone’s help!

Picture gallery

Summary
Footprints on red dot sights
Article Name
Footprints on red dot sights
Description
In this article, the most common footprints/mounting standards used on red dot sights are listed. Each standard is described and an image of it is added.
Author
Optics Info
Optics Info
Optics Info

71 thoughts on “Footprints/Mounting Standards on Red Dot Sights”

  1. Mounted the Holosun 507c on G45 MOS. Perfect fit with zero play and 6 lbs of tork using Blue Loktite. EDC weapon and must train on presentations but have used the Venom for a few years without issue. Right handed but blind in right eye and left eye now not able to focus on FSP. Put off the red dot fad until last year. Not a fad and much easier and faster than irons. Always keep irons on weapon as backup. Train as mush as possible at dot acquisition from your EDC holster.

    1. Why would you want that – you elevate the sight that way, you wanna have it as low as possible. Im sure there is one from a 3rd party supplier.

  2. Just receive my canik elite subcompact with optic ready . I was interested on getting a red dot optic but dont know which one I should go with. I know I want to try and stay around the 200 dollars range so any help would be appreciated. Thank you

  3. This may seem like a dumb question but is it pretty well confirmed that the Holosun 507K and the Shield RMSc share the same footprint? I’m seeing a lot of slide milling companies that don’t have 507K on their website yet but they do have Shield RMSc so I’m assuming if they’re the same it’s safe to order that and it would still be compatible with the Holosun 507K. Thanks for your help.

    1. Dave,

      sorry for the late reply.

      The footprint is not exactly the same. 407K/507K feature a modification of the Shield SMS/RMS footprint, which means that some handguns will have to be slightly modified for these red dot sights to fit.

      More information is already available in the article (it has been updated).

  4. Andraž,

    Per your article, 507k and DDP have the same footprint, and the Sig Romeo 1 Pro should have the same footprint as the DPP. So will the Holosun 507k install directly on a Sig P320 Xcompact?

    1. Dear Marcus,

      From what I’ve heard, Sig Sauer Romeo 1 Pro should have the same footprint as Leupold DPP (the standard DPP has a unique footprint).

      As 407K/507K feature a modification of the Shield RMS/SMS footprint, it would be best to contact Sig Sauer directly and inquire whether any modifications to the handgun are necessary.

  5. This is an awesome source of info; I did however find a discrepancy with the shield standard and the holosun 407k/507k optics. On the optic body, there are no recesses for the rear posts, so those will have to be removed in order to accommodate that particular optic.

    1. Dear Matt,

      thank you very much for your comment.

      Yes, we received the first 407K/507K sights on Friday and found out that two sockets are missing at the back. The recesses in the front appear to be shorter, too. I have just updated the article.

  6. Thank you for putting this resource together! I’ve referred to it multiple times as I’ve purchased red dots for several pistols over the past 6-8 months.

    I have a question I’m hoping you or a reader might be able to answer: does the Vortex Viper and Burris FastFire 4 share the exact same footprint? I ask because I have a slide that’s milled for a Vortex Viper but I want to replace the Viper with the FastFire. However since the slide was milled for the Vortex and fits it exactly I’m not sure that the FastFire will fit the milled area. It looks like the front of the FastFire is curved more than the Viper, but I can’t find any footprint schematics that provide a definitive answer.

    1. I am glad to hear that the article has been of help to you as this is its main purpose.

      We still haven’t received a Burris Fastfire 4 to check its footprint. I’ve heard several times from multiple sources that it has a Docter footprint, but I can’t confirm that until I see the footprint personally and do all the measurements.

      It will surely be added to the article as soon as we get it.

  7. Can someone help me ? I would like to mount a Romeo3max on a SigSauer P226 X-Five skeleton. Is that possible? What assembly would I need?

    P.S .: Great article!

  8. Excellent and thorough article.

    I have a question regarding a possible adaptor, I have a side mount AK rail that is topped to receive only a T1/H1 style optic but in my inventory I only have picatinny mounted optics, are there any suggestions for converting a T1 base to standard picatinny? There are many that convert from picatinny to T1 but nothing the other way around.

    Below are links to the rail in question.

    https://www.centuryarms.com/ak-side-mount.html
    https://www.opticsplanet.com/century-ci-ak-side-scope-rail-mount.html

    Thank you!

    1. thank you for the kind comment.

      Unfortunately, I am not aware of any adapters that would convert the Aimpoint Micro footprint into a Picatinny. As you said, there are many on the market that convert the Picatinny rail into an Aimpoint Micro footprint, but I haven’t seen any yet that would convert the other way around.

  9. Hello, have you noticed some other not-that-famous red dots like VISM Flip-dot or Swampfox Kingslayer?
    I’ve seen some images that the VISM Flip-dot has the same footprint as the Trijicon RMR. It together with the Kingslayer are both some interesting red dots, i hope these two can be concluded in the webpage as well(⁎⁍̴̛ᴗ⁍̴̛⁎)

    1. These two red dot sights sure look interesting. I haven’t had the option to see them live, but I’ve checked the web and they are listed as having the RMR footprint, so I added them to the article.

      Thank you!

  10. I’m looking to put a Sig Romeo Zero on my APX full size and I’m wondering which of the Beretta mounts I would need to purchase, any thoughts?

      1. RomeoZero, Shield RMSc and Holosun 507k (presumably the 407k as well) share a footprint. I’ve had all three of these on a Sig P365XL.

  11. This is an excellent resource.

    I have a question: from the photos it seems that the screw holes for the GPO Spectra are spaced longitudinally closer than Aimpoint Micro’s? I’m asking because I have a mount that is similar to a Micro but its holes are spaced 3mm closer lengthwise and thus don’t fit my T1 red dot. Any help would be much appreciated!

    1. It does seem like that from the photo, but the holes on both footprints are actually of the same distance from one another.

      To be honest, I don’t know of any footprint where the holes would be 3 mm closer together lengthwise – but then again, I haven’t seen all the red dot sights yet.

  12. Andraz,
    This was a very informative article. What I didn’t see noticed separately was the DeltaPoint Pro. I have a DPP that I would like to mount on an aftermarket Glock 19 slide (yet to be purchased) with a slide cut for a red dot. The problem is, the slides that I’m looking at (Zev, etc.) don’t come with a cut specified for a DPP. They’re mostly configured with Burris FF, RMR or Vortex Venom cuts. Judging by one of the specs, DPP shares the Shield footprint, but there aren’t many/any slides offered with Shield cuts. ANy thoughts?

    Thanks,
    Scott

      1. Are you referring to the raised shank or do you mean the overall plate? The shank would be the critical dimension. If they are different, can you please post the specs so we can all know this?

  13. Having a hard time finding mounting plat for my Nikon tactical spur. Really wanted to mount it on walther Q4 tac m2 walther doesn’t have one either ? Any help would be appreciated. I’m thing I will be kipping this Nikon on my rifles with a rail on it…. Thanks

  14. I have a slide with RMR/507c cutout, and would like to mount a Fastfire 3 (Docter footprint). Is there an adapter that will work? So far all I have found is the opposite, an adapter that allows you to mount a RMR/507c to a Docter footprint slide.

    1. J-Point has the same footprint as Shield RMS, SMS, and Leupold DeltaPoint Pro, so this basically converts the Shield footprint to a Docter/Noblex footprint. Maybe it also works for the RMR, but no picture shows the bottom part.

  15. I have a Walther PPQ Q4 and Q5 Steel frame handguns and am considering the newer Sig Sauer Romeo 3 Max and XL for these guns. Do you have mounting plates that would allow this? I see the standard Romeo 3 listed but the Max and XL are slightly larger and may have a different footprint.
    Thanks

    1. Sig Sauer Romeo 3 Max has a C-more footprint – I’ve just checked it (it will be added to the article shortly). We do have a solution made by EGW in our offer:

      https://www.optics-trade.eu/en/egw-vortex-razor-sight-for-walther-ppq-m2.html (it says it is made for Vortex Razor which also has the C-more footprint)

      More information is available here: https://www.egwguns.com/vortex-razor-walther-ppq-sight-mount-fits-c-more-sts-sts2-rts2

      The adapter won’t fit your pistol if it is optics ready.

  16. Thanks this is the most helpful information I have found yet on red dot sights and mounts, which can be very confusing for someone not educated in red dot optics, thanks again.

  17. Awesome resource. And still the only comprehensive listing of reflex/red-dot footprints on the web. Great job keeping it up to date too. I’ve used it multiple times to figure out what sites will fit a given cut and sent others here when they have a question about fitment.

  18. If anyone has access to a compilation of these footprint files, I can easily turn them into CAD files and make these plates. I’ve got three HAAS mills that can make a ton of them.

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