FAB Defense FXFRBS Front/Rear Folding Back-Up Sights AR-15/M16/M4 Dual Aperture Rear Black

The FAB Defense FXFRBS is a low-profile, folding front and rear back-up iron sight set purpose-built for the AR-15, M16, and M4 platform. Designed as a durable auxiliary sighting system, the FXFRBS mounts directly to any 1913 Picatinny rail and folds flat when not in use, leaving a primary red dot or magnified optic completely unobstructed until needed.

The rear sight features a dual aperture configuration, offering a small aperture for precision shooting at distance and a larger aperture for fast close-quarters aiming. Both the front and rear sights provide tool-free windage adjustment, allowing rapid zeroing in the field without specialty tools. The construction pairs a rugged polymer body with metal internal components for a lightweight yet durable package, finished in a non-reflective black.

Compact, lightweight, and purpose-built as a reliable fail-safe, the FXFRBS gives any AR-pattern carbine an instant transition to iron sights should an electronic optic fail, run flat, or simply be cleared from the sight picture. This is a brand-new, factory-fresh accessory ready to install on your rifle.