Aimpoint COA Mounts

Aimpoint COA mounting standard

The Aimpoint COA enclosed red dot sight and its proprietary mounting standard were first publicly introduced in 2025. The mounting standard originated from a joint development project between Aimpoint and GLOCK. The goal of the collaboration was to develop an ultra-low-profile enclosed pistol optic system with improved durability, direct mounting capability, and enhanced ergonomics.

Aimpoint COA Footprint

Aimpoint COA Mounting Standard

The COA mounting standard was developed in parallel with the Aimpoint A-CUT direct-mount interface introduced for selected GLOCK pistols. Unlike the Aimpoint ACRO mounting standard, the COA standard does not use side clamping grooves or side tightening screws. Instead, it relies on a proprietary wedge-style locking system combined with elongated recoil support rails positioned along the sides of the mounting surface.
Unlike the earlier MOS platform, the COA/A-CUT system was designed as a dedicated direct-mount solution rather than a universal adapter-based interface. The mounting interface allows the optic to sit exceptionally low within the slide cut, resulting in a very low optical axis height. The recessed mounting area is approximately 1.5 mm deep, allowing the optic to sit very close to the slide and, in some cases, enabling co-witnessing with standard-height iron sights. Due to the low optical axis height, the system provides a more natural sight alignment while maintaining a compact overall profile.

The mounting standard measures approximately:

43.5 mm in length
24 mm in width
44.7 mm maximum base length
14 mm internal rail spacing

The system was originally developed for enclosed reflex sights intended for handguns, with early factory implementations appearing on GLOCK pistols equipped with the dedicated A-CUT interface.

The design philosophy focused on several key advantages:

low-profile direct mounting into the slide
improved recoil resistance and durability
elimination of adapter plates
reduced overall optic height
improved sight acquisition and shooting ergonomics

The mounting interface is designed to distribute recoil forces across multiple contact surfaces rather than relying solely on mounting screws, helping to improve mechanical stability under recoil.
The COA/A-CUT platform was also designed as a largely closed ecosystem. Unlike universal mounting standards such as Trijicon RMR or Aimpoint ACRO, the system prioritizes maximum rigidity and minimal mounting height over broad cross-compatibility. The Aimpoint COA mounting standard is therefore proprietary and not compatible with mounting standards such as Docter/Noblex, Trijicon RMR, Shield RMSc, or Aimpoint ACRO.

Aimpoint COA Mounting Standard

Although the COA standard was initially developed for pistols, the ecosystem is gradually expanding into rifle-oriented applications and mounting solutions such as the COA-R platform.
The COA platform is still relatively new and not yet as widespread as standards such as RMR or ACRO, but it represents a modern approach to low-profile enclosed pistol optic mounting systems.
Compatible mounting solutions are currently offered primarily by Aimpoint and selected manufacturers including Recknagel, Era-Tac and Spuhr.