Magpul Industries, MBUS Back-Up Front Sight Gen 2, Fits Picatinny Rails, Flip Up, Olive Drab GreenThe MBUS (Magpul Back Up Sight) is a low cost, color injection molded, folding back up sight. The MBUS Front Sight is adjustable for elevation and fits most 1913 Picatinny railed hand guards, but is specifically tailored to the AR15 M16 platform. Features : Spring loaded flip up sight Easily activated from either side or by pressing the top Protective wings shield the spring locking A2 front sight post Polymer construction provides light weight and