The Fab Defense Front Back-Up Sight FX-FBS is a compact, low-profile front sight designed to give AR-15, M4, and M16 shooters a dependable aiming reference whenever optics are not an option. Built from high-grade polymer and metal, it folds flat until needed, then snaps into place with a secure spring-locked mechanism for a clean, repeatable sight picture on any 1913 Picatinny rail.

This front sight can serve as either a primary or backup option, pairing seamlessly with most rear sights and especially with the matching Fab Defense RBS rear sight to form a precise optical tunnel. Tool-less elevation adjustment lets you fine-tune your zero quickly at the range, while the smooth, snag-resistant folded profile makes it well suited for training, general range use, and duty-style rifles. Fab Defense’s attention to detail and durable construction make this sight a practical upgrade for shooters who value reliability and clean design.

Key Features:

• Manufacturer: FAB Defense
• Model: FX-FBS Front Back-Up Sight
• Product Type: Flip up front sight
• Style: Folding, low-profile design
• Mounting: Fits standard 1913 Picatinny rails
• Adjustment: Tool-less front sight elevation
• Construction: High-grade polymer and metal