The UST® Tent Bulb 0.5 is the perfect addition to your key chain, backpack, purse, or wherever you want to have a little light. It has convenient carabiner attaches light to wherever you want. With easy twist on / off operation. That uses four LR41 cell batteries (included). Available in Orange/Gray. Dimensions: 4.25" x 1.25" and Weight: 0.6 oz.