This perhaps the most powerful EDC keychain flashlight available in the marker right now, the Nitecore T4K got a 4000 lumen output of brightness.... "This is your chance to own a superlative and carry it around every day. The Nitecore T4K is the world's most compact 4000 lumen (10 second burst) keychain light. That translates to over 228 yards of throw and illumination from a thumb-sized keychain light. The keyring has a built-in mechanical quick release design for fast deployment and usage. Additionally, with the included adjustable pocket clip, you have an ideal EDC companion. Here to stay is the intuitive dual button design with instant turbo making the T4K a must have accessory for any keychain, emergency kit, or outdoor set."