3 AA Standard Alkiline Battery(Not Included), Rechargeable battery is not recommended! | 51 UV LED allow to cover a larger area.Emits 390 to 395 nanometer wavelength. | Perfect for outside use such as finding scorpions and minerals! | Tips:in order to keep the flashlight's lifetime,if you did not use it for a long time,please put off the battery. | Improper usage of batteries or using poor quality of batteries could cause hazard issue to your safety.We recommend to use reliable quality batteries.Any issues caused by batteries DO NOT covered by the manufacturer warranties.