The beauty of the Columbo Keychain Pocket Light is its' simplicity and convenience. No need to cycle through multiple light modes, simply activate it with the easy, one-hand twist operation. Built from aircraft-grade aluminum, the housing is anodized for corrosion resistance and it is waterproof and impact-resistant. The 100 lumen LED runs on a single AAA battery and the removable keyring lets you attach it to your car keys, a backpack or purse so it is always close at hand. Measuring at just over 3-inches in length and less than 1-inch in diameter, it is not much larger than a lip balm or a pack of gum. Thanks to the Columbo Keychain Pocket 100 Lumen Flashlight, there's no excuse to not have a light so you're prepared for the unexpected.