F.A.B Defense RBS Folding Back-Up Sights

RBS 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® K.P.O.S.

Advantages:

Can be used as primary or back-up sight

Ergonomic angel-wing-shaped shroud helps center the image with any front sight, and when used with a matching FAB Defense® FBS Front Back-up Sight, it creates a precise optical tunnel that ensures more accurate aiming and faster target acquisition

Dual apertures are 3mm for longer eye relief mounting, low light, and faster target acquisition; and 1.5mm for shorter eye relief mounting and greater accuracy; each is instantly selectable to match conditions

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 windage adjustments, with positive detent locking

Made of extremely durable high-grade polymer and metal