
Availability: In Stock
The FAB Defense FXFBS polymer flip-up front sight for AR-15, M4, and M16 platforms gives you a reliable backup aiming solution that works equally well as your primary optic. Built from durable high-grade polymer and metal, this flip-up sight folds low and tight against your upper receiver when not in use—no snags on your gear or brush, no compromises on a clean profile. Deploy it instantly with a spring-locked mechanism that stays put once flipped up, no slipping or deforming under hard use.
The real advantage shows up when you pair this front sight with FAB Defense's matching RBS rear backup sight. Together, they form an optical tunnel that centers your sight picture and speeds up target acquisition in a way single sights can't match. The ergonomic angel-wing-shaped front shroud naturally helps frame and stabilize your sight image, whether you're using it standalone or as part of a matched pair. That design pays off on the range, in the field, or when zeroing a new optic setup.
Elevation adjustments require no tools—turn and lock, with positive detent stops that hold your zero. The flip-up design means you can stow it down when your primary optic is doing the work, then bring it back into action in seconds if needed. It's the kind of no-fuss, work-hard backup sight that AR shooters count on.
The FAB Defense FXFBS is compatible with AR-15, M4, and M16 rifles.
You can deploy it as your primary sight. However, it's designed to pair with FAB Defense's matching RBS rear backup sight to create an optical tunnel that improves accuracy and target acquisition speed.
Installation and elevation adjustments need no tools. The positive detent locking system holds your zero without additional hardware.
The sight folds to a low profile that won't snag on gear, webbing, or brush when stowed, keeping your upper receiver clean and your kit quiet.



SKU: 115855954 • Width: 3.2in • Height: 1.4in • Depth: 5in • Weight: 0.19oz





Availability: In Stock
The FAB Defense FXFBS polymer flip-up front sight for AR-15, M4, and M16 platforms gives you a reliable backup aiming solution that works equally well as your primary optic. Built from durable high-grade polymer and metal, this flip-up sight folds low and tight against your upper receiver when not in use—no snags on your gear or brush, no compromises on a clean profile. Deploy it instantly with a spring-locked mechanism that stays put once flipped up, no slipping or deforming under hard use.
The real advantage shows up when you pair this front sight with FAB Defense's matching RBS rear backup sight. Together, they form an optical tunnel that centers your sight picture and speeds up target acquisition in a way single sights can't match. The ergonomic angel-wing-shaped front shroud naturally helps frame and stabilize your sight image, whether you're using it standalone or as part of a matched pair. That design pays off on the range, in the field, or when zeroing a new optic setup.
Elevation adjustments require no tools—turn and lock, with positive detent stops that hold your zero. The flip-up design means you can stow it down when your primary optic is doing the work, then bring it back into action in seconds if needed. It's the kind of no-fuss, work-hard backup sight that AR shooters count on.
The FAB Defense FXFBS is compatible with AR-15, M4, and M16 rifles.
You can deploy it as your primary sight. However, it's designed to pair with FAB Defense's matching RBS rear backup sight to create an optical tunnel that improves accuracy and target acquisition speed.
Installation and elevation adjustments need no tools. The positive detent locking system holds your zero without additional hardware.
The sight folds to a low profile that won't snag on gear, webbing, or brush when stowed, keeping your upper receiver clean and your kit quiet.
SKU: 115855954 • Width: 3.2in • Height: 1.4in • Depth: 5in • Weight: 0.19oz


