KAC-Knight’s Armament Modular Ambidextrous Select Fire (Full Auto) Safety Selector Series M4 (113897) This kit replaces the 25897 kit The KAC Ambidextrous Safety Selector Series 2 Kit includes 3 different selector options for each side to suit individual shooter preferences There is the choice of a full size selector lever, a semi-scalloped selector that is low profile and less obtrusive, a short lever and an indicator arrow that provides a visual indication of the rifle’s firing mode only Installation is a simple, drop-in procedure. Compatible with both M16 and M4 platforms Full-auto only