The Magpul MBUS Pro LR rear sight is an all-steel, folding backup sight with a low-profile footprint that co-witnesses with most red dots and clears optics when stowed. The LR (long-range) version adds a windage-adjustable aperture and range-oriented sight picture for precise iron-sight shooting out to distance. Snag-free, corrosion-resistant, and built for duty. Black.