YDP-SPORT Cree XML2 Led Scuba Diving Flashlight Torch Power by 18650 Rechargeable Battery (Included) with Charger (Included) Underwater 50M for Diving and Outdoor Lighting Used the Ultra Cree XML2 LEDs Powered by one 18650 Li-ion 3.7V 2200mAh rechargeable battery,the scuba light comes with a rechargeable battery and a charger to charge it. It's great that it comes with its own battery. To turn it on, it's more like a sliding button rather than one you can flip on/off. This flashlights output can be high/medium/low and a little flickering of light is noted upon sliding the control.Stated to operate on "High" for 2 hours, "Medium" 2 to 10 hours, and "Low" 30 hours with included battery Our diving light is IP68 waterproof to 50 meters,it does great underwater. If you need the diving flashlight it is your best choose. Made by anodized aircraft 6061 aluminum the material feels pretty solid and when I put it in some water, it was fine. It's super bright and would be great for going to a beach at night. Complete package included Led Diving Torch, Rechargeable battery, Charger and Wrist strap, Full Set ready for using