Footprint

Footprint in red dot sights refers to the specific size, shape, spacing, and placement of mounting holes on the bottom of the optic, which serve to attach the red dot sight to a weapon or adapter (such as MOS / OR and others). Each footprint type follows a specific standard and is not cross-compatible without an appropriate adapter. Choosing the correct footprint is essential for compatibility between the red dot and the firearm slide or mounting system. RMR and Docter MRDS are the most common. Always verify the footprint type for both the weapon and the red dot sight or use an adapter. Most red dot sights are also supplied with a RIS mount, which ensures universal attachment but is not suitable for direct mounting on pistol slides.

Most common footprint types and examples of red dot sights

RMR footprint (Trijicon RMR / SRO standard)
Typical setup with 2 screws + 2 guide pins at the rear.
Red dots: Trijicon RMR, Trijicon SRO, Holosun 407C/507C/508T, Vector Optics Frenzy 1x20x28
Usage: Pistols (Glock MOS, CZ OR), carbines, military applications.
Most widespread in service use (e.g. USSOCOM).

Docter / Noblex footprint
Flat profile with two rear screws, widely used in Europe.
Red dots: Docter Sight II/III, Noblex Sight C, Burris FastFire, Vortex Viper/Venom, Vector Optics Frenzy 1x17x24
Usage: Pistols, shotguns, optics on hunting rifles.

RMSc / Shield footprint
Very compact footprint, ideal for micro red dots on slim subcompact pistols.
Red dots: Shield RMSc, Holosun 407K/507K, Swampfox Sentinel, Sig Romeo Zero
Usage: Pistols like Glock 43X MOS, Sig P365X, Springfield Hellcat OR.
Very popular in the civilian CCW market.

MOJ footprint (Mounting Optics J-Arm)
R.M.R. standard used in civilian shooting and airsoft, e.g. by Tokyo Marui for their collimators and adapter for TM Glock 17. Basically, it is an RMR footprint (compatible with Trijicon RMR, SRO), but intended for civilian shooters including airsoft replicas that do not have a license from Trijicon to use the RMR name.
Red dots: Same as RMR footprint, Vector Optics MOJ red dots and airsoft red dot replicas such as Tokyo Marui Micro Pro Sight.
Usage: Civilian weapons and pistols, airsoft weapons, specific use for the Japanese market and hobby segment - where the RMR license designation cannot be used.

Aimpoint Micro footprint
Typical for tube-style red dots with side-mounted bases.
Red dots: Aimpoint T-1, T-2, Holosun 403B, Vortex Crossfire Red Dot
Usage: Rifles and carbines, common in military use.

ACRO footprint
Fully enclosed red dot sight with built-in rail and specific mounting.
Red dots: Aimpoint ACRO P-1 / P-2, Steiner MPS.
Usage: Military weapons, pistols and rifles. High durability. Widespread in professional use.

Popularity in the world and airsoft

Most popular in the military: RMR footprint due to the widespread use of Trijicon RMR (e.g. by USSOCOM) and compatible Holosun models.
Most popular in the civilian market: Docter and RMSc for their compatibility with commonly available red dots.
Airsoft: Docter and RMR footprints are the most used – for mounting on pistols and AEG replicas. In airsoft, aesthetics and ease of mounting are more important than ballistic durability.

Vector Optics red dot footprints

Vector Optics uses several types of mounting footprints for its red dot sights, which determine compatibility with weapons and mounting plates. Each footprint has specific dimensions and mounting hole layouts. According to the provided diagram, we distinguish the following types:

VOD™ – Compact footprint with straight edges, dimensions 42 x 31 mm. Mounted with two screws spaced at 26.6 mm and 17.6 mm.
MOJ™ – Classic footprint with rounded front, very similar to Docter/Noblex. Dimensions 45.3 x 27.6 mm, four mounting holes, two main ones spaced at 22 mm.
TEK™ – Larger base (48 x 29 mm), with a dominant circular hole and two mounting points spaced at 24 mm. Suitable for heavier red dots.
MGT™ – Footprint with four mounting screws arranged diagonally, total size 41 x 25.9 mm. Mounting holes spaced at 24 mm and 33.8 mm.
RUM™ – Long base measuring 54 x 24 mm. Four mounting points symmetrically spaced at 14.5 mm. Typical footprint for tactical tube red dots.
GIN™ – Largest footprint in the range, 58 x 37.5 mm. Hole layout spaced at 29, 17, and 15 mm. Designed for high-stability optics and heavy-duty mounting.

When selecting a red dot sight from Vector Optics, it’s always important to check the footprint specification and make sure it matches the mounting plate on your weapon (e.g. MOS / OR / RIS). An incorrect combination may prevent proper installation or cause the optic to shift during shooting. This overview also serves as a reference when choosing adapters or direct mounts for pistols and carbines.