UST Tent Bulb .5 LED 2.5 Lumen Keychain Light with Durable Construction and Handy Carabiner for Backpacking, Hiking, Camping, Emergency and Outdoor Survival BRIGHTNESS: 2.5 lumens of light DIMENSIONS: 4.25 L x 1.25 W and weighs 0.6 oz with (4) LR41 batteries (included) EASE OF USE: Easy twist ON/OFF operation RELIABLE: Features a carabiner to attach to a tent, small tree limb, or any outdoor gear DURABLE: Runs on long lasting LED bulbs