UTG Super-Slim Picatinny riser that adds 0.5 inch of height for co-witness or a more comfortable sight position. The 3-slot, 1.57-inch footprint keeps weight and length to a minimum. Features: 0.5-inch riser height 3 slots, 1.57-inch length Fits 20mm Picatinny and Weaver rails 6061-T6 aluminum, matte black anodized CNC machined Scalloped slots Light weight, about 0.92 oz Use it to set a red dot at a co-witness or comfort height on a flat-top Picatinny rail.