The FAB Defense FBS is an advanced, low-profile, durable, auxiliary front sight. It can be used with any rear sight, but has been designed to provide an extreme optical advantage when paired with the FAB Defense RBS Rear Back-up Sight. Sight pin elevation is easily and quickly adjusted without tools. The FBS is readily mounted on any 1913 Picatinny rail, making it ideal for use on M4 / AR-15 / M-16 platforms and on the FAB Defense KPOS. FeaturesCan be used as a primary or back-up sightErgonomic 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 acquisitionLow folded profile is smooth and inconspicuous, and will not snag on gear, webbing, or brushInstant spring-locked deployment mechanism will not slip, break or deformNo tools needed for easy, rapid elevation adjustments, with positive detent lockingMade of e...