This LED Tumbler Handle not only makes your 20oz. or 30oz. tumbler easier to hold and carry, but also gives you the power of light without moving a finger. No more slipping, dripping or tripping in the dark while trying to balance your tumbler when your hands are full. This LED Tumbler Handle fits most standard vehicle cup holders, and perfectly holds your tumbler secure with the rubberized grip ring. Powered by 3 AAA batteris, already included in the handle.