For 1913 Mounted Lights - KeyMod Version. Fully ambidextrous: made to mount flush or cantilever off either the left or right side of the rail system. Optional high and low mounting position for the 1913 rail section. Fits most common 1913-rail pistol/weapon light systems Multiple mounting holes for ideal placement. Designed to mount on the 3 or 9 o?clock rail positions. Durable Aluminum construction. Intently designed to be low-profile and snag-free Patent Pending mounting system Minimal added weight, 0.9 oz. Installation Instructions : 1. Ensure the weapon system is unloaded and clear, prior to performing any maintenance. 2. With supplied Torx wrench, loosen (counter clockwise) and remove the two mounting screws and the one recoil lug screw (reverse thread). 3. Of the six mounting position holes on the mount, select the desired holes for all three screws. Note: mounting screws and recoil lug screw placement will vary, depending on mount placement, left or right hand side of the rail. 4. With the mounting screws location selected and the screws loosened, locate the desire KeyMod placement on the rail system, install and slide forward until it travels no further. 5. Select high or low position for the 1913 rail section and install the screws. 6. Tighten all screws (clockwise) until firmly secured (30 in-lbs) For a better, more secured hold, use blue thread locking compound on mounting screw thread only.