Can be used as a primary or back-up sight Ergonomic angel-wing-shaped front shroud helps center the image with any rear sight, but when used with a matching FAB Defense RBS Rear Back-up Sight, it creates a precise optical tunnel that ensures more accurate aiming and faster target acquisition Low folded profile is smooth and inconspicuous, and will not snag on gear, webbing, or brush Instant spring-locked deployment mechanism will not slip, break or deform No tools needed for easy, rapid elevation adjustments, with positive detent locking Made of extremely durable high-grade polymer and metal