MecArmy Illuminex 3 130 Lumen Super Mini Rechargeable LED Keychain Flashlight with Micro USB Interface (Copper) The World's Smallest USB Rechargeable Flashlight Quick Charge Micro USB Interface Reliable Tail Twist Switch for quick, one-handed operation Uses a rechargeable 10180 lithium ion rechargeable battery Waterproof to IPX-8 Standard (submersible up to 2 meters)