The FAB Defense FRBS offset folding back-up sight kit in the left-hand, black version (FAB Defense part no. FXFRBSOSLHB) gives you iron sights that sit off to the side of a Picatinny rail until you need them. FAB Defense designed the set as a back-up for use with magnified optics during close-quarters work, with the rear and front sights folding down to leave the rail clear. It keeps the profile low, with minimal protruding parts that are less likely to snag. Adjustments need no tools. This left-hand version mounts to the standard 1913 MIL-STD Picatinny rail.

Key Specifications

• The sight set is the left-hand offset version, which FAB Defense also makes in a right-hand variation.
• The finish is black, which blends with most rails and receivers.
• It mounts to a 1913 MIL-STD Picatinny rail, so no adapter is needed on a standard rail slot.
• The rear sight adjusts manually for windage and the front sight adjusts manually for elevation, with no tools required.
• Construction is fiberglass-reinforced polymer and metal, a combination that keeps the weight down without giving up durability.
• Folded, the sights measure 60 mm long, 24 mm wide and 51 mm high, a compact footprint on the rail.
• The set weighs 59 grams and deploys to 73 mm long and 43 mm high.

Frequently Asked Questions

What is the FRBS kit designed for? FAB Defense designed it as a back-up sighting solution for use with magnification lenses during close-quarters scenarios, with a sleek design and minimal protruding parts.

Is this the left-hand or right-hand version? This listing is the left-hand version in black. FAB Defense also offers the offset kit in a right-hand variation.

What rail does it attach to? It is compatible with a 1913 MIL-STD Picatinny rail.

Buy the FAB Defense FRBS Offset Folding Back-Up Sight Kit, Black, Left Hand

Back-up sights only earn their place if they stay out of the way until needed, which is the whole idea of an offset folding set. Order it from our Lubbock, Texas gun shop, or browse more gun sights, for fast, direct shipping.