MBUS Sight - Rear, RET, Stealth Gray,
MBUS Sight - Rear, RET, Stealth Gray,, The MBUS (Magpul(R) Back-Up Sight) is a low-cost, color injection molded, folding back-up sight. The dual aperture MBUS Rear Sight is adjustable for windage and fits most 1913 Picatinny rail equipped weapons, but is specifically tailored to the AR15 / M16 platform.