GEARTOUCH MBUS 2 Front & Rear Back-Up Sight Set - Black Polymer Sights Pair Front and Back Mount Set Front and Rear BACK UP SIGHTS BU Rear Sight Weight, w/ hardware: 1.3 oz. Height above rail, stowed: ~0.51 in. Center of aperture to top of rail: 1.42 in. Length, stowed: 2.6 in. Length, deployed: 1.5 in. Front Sight Weight, w/ hardware: 1.2 oz. Height above rail, stowed: ~0.51 in. Length, stowed: 2.6 in. Length, deployed: 1.5 in.