This is a Mako GIS Glock Optic Mount. Mount compact optics on Glock pistols with front accessory rails. Excellent for use with Glock stocks. Allows use of iron sights. Fast sight alignment. Improves balance and recoil control. Mounts to frame, so optic remains stationary, does not slam back and forth with slide. Rigid design mounts to three points - pistol rail and each side of trigger pin. Top picatinny rail for mounting compact red-dot optics. MIL-SPEC reinforced polymer composite. Weight - 1.98 ounces (56 gr). Width - 1.4" (36 mm). Height - 2.8" (70 mm). Length - 4.3" (110 mm).