Olight PL-1 II Valkyrie 450 Lumen LED Weaponlight. The PL-1 II is our refined and upgraded version of the original PL-1 weapon light. We have spent over a year in development for this project producing countless prototypes to create the perfect weapon light that our users can depend on for years. We have dramatically increased the strength of the mounting mechanism that will NEVER become loose or fall off of any firearm that has a rail. Our dual spring system and insulated interior protect the light from any recoil or temperature change that the light encounters. We have included a rail insert and tool to change for the 1913 and Glock style rails so it can fit any type of firearm you have with perfection. The UI is extremely natural and simple so that the user can think of what they need to when using it rather than worrying about their light. We had several shooter sat gun ranges try out the light without telling them how to use it. Without saying anything, they already started using it like they have been for years. We have tested this light on every Pistol and Rifle that we could think of shooting thousands of rounds over the past year and the same result always happens, it always works and it never gets loose. This is what a firearm owner has dreamed of, a perfect light at an affordable price backed by our signature 5-year warranty. If you own a firearm that has a rail, this is it. FEATUERS: Applicable on MIL-STD-1913 and Glock sized rails Uses a single CR123A battery delivering an output of 450 lumens and a beam distance of 106 meters Switch on/off silently. Push forward directly or hit the side of the switch to activate Heavy duty stainless steel lever making it easy and fast to attach and release Hardened glass coated with an anti-reflective coating on both sides allowing for 99% light transmission rate for maximum clarity IPX6 Waterproof --Output: 450 Lumens for 60 minutes --Size: 3.1" x 1.22" x 1.49" --Weight: 3.37 oz excluding battery