FAB Defense FXRBS Rear Back-Up Sight AR-15/M16/M4 Dual Aperture Black Polymer/Metal

The FAB Defense FXRBS Rear Back-Up Sight is an advanced, low-profile auxiliary rear sight built for AR-15, M4, and M16 platforms. Designed as a dependable backup to primary optics, this flip-up sight mounts to any 1913 Picatinny rail and deploys via a spring-locked mechanism for quick, confident activation.

Featuring a dual aperture configuration, the RBS provides two aperture options for varying engagement distances. Windage adjustment is easy and quick, performed without tools for fast zeroing on the range. The sight folds down to a low, snag-free profile and locks securely in place.

Constructed from a durable combination of polymer and metal components in a black finish, the FXRBS keeps weight to a minimum while standing up to hard use. It is an ideal auxiliary sighting solution for rifle builds, carbines, and duty setups where a reliable iron-sight backup is essential.