MECO Pack of 3 Mini Keychain Flashlight Rechargeable Dynamo Wind-up Torch for Key Ring Emergency Hand Powered, Wind it up for one Minute and will supply for the flashlight on for about 5 minutes. Bulit in rechargeable battery.No need to replace the battery.Wind it up and the flashlight will work Can store the energy.Wind it up when you've free time and energy will be stored and use late. Mini and light weight,great for emergency.Wind-up as power supply. Switch to turn on and off. 100% Brand New,18-month warranty since the purchase date, 40-days money back guarantee