The unique design of the spring loaded rear sight, ensures constant battery action and repeat zero. The sight is held in the locked down position by a quick release lever, that prevents the sight from being accidentally engaged, but is as fast as a trigger to release even with arctic mittens. The initial elevation zero utilizes the standard M16/M4 front sight bead. When the sight is released into battery the 250-300 meter aperture is ready for immediate close combat use.