If you plan to mount on ar9 or ar pistol this is necessary - Olight RPL-7 Magnetic Remote Pressure Switch for PL PRO Flashlight

If you plan to mount on AR9 or AR pistol this is necessary. Only thing id change is add in a temporary strobe of light function button. Its on or off basically because the pad it pretty se sative but is designed to hold and release for temp and click for on/off. Overall im veey satisfied. It works and the light is stupid bright gkr just a pistol.