Never needs batteries. Cranking restores the rechargeable batteries to their charged state. Nichia LEDs are bright, virtually unbreakable and never need replacing. 3.6 volt 80 mAH NiMH non-replaceable battery pack is charged with the crank only. Crank operates in either direction. Quick to use carabineer clip makes it easy to hang and remove light. For extended power outages and situations where the light will be stored for long periods of time. Typical weight of 111 grams. 134 mm x 55 mm x 35 mm.