BESTSUN LED Flashlight Waterproof Portable Cree XM-L Headlamp 750 lumen Cree XM-L LED Headlamp Battery Type: One 18650 size (up to 67mm long) 3.6/3.7V Li-ion rechargeable battery (not included). Electronic soft-touch switch Waterproof to IPX8 (2 meters, 30 minutes) Smart user interface provides fast and easy access to all brightness levels