Keychain LED Flashlights Small Keychains for Men and Women Keychain flashlight 100 lumen high-brightness High LED beam, Up to 10 Thousand Hours. Unique water proof aluminum-magnesium alloy shell. 3.7'' Length X 0.74 Diameter - Weight 1.76 OZ light, and solid. Runs with only one AA battery. Keychain led light (Battery not included)