ULTRA COMPACT AND LIGHTWEIGHT - Weighing in at just 3.16 oz and measuring just 2.54 in long, youll hardly notice the low profile NPL20 on your weapon. DURABLE - The NPL20 is made from aero grade aluminum alloy with an HA III military grade hard-anodized finish. It is IP67 dust and waterproof rated, with impact resistance up to 1 meter. SIMPLE INSTALLATION - The Nitecore NPL20 is a compact rail-mount flashlight that is compatible with most handgun models with over 4 inch barrel length and Picatinny accessory rail. Installation is a breeze, requiring you to turn only a single screw. EASY TO OPERATE - Press and hold either side button to access tactical momentary-on, short press either button to access constant-on, and triple press either button for STROBE Mode, which uses nonlinear strobe frequencies for stronger dizzying effects.