Transform your multi-fuel, high-performance weapon lights into rechargeable systems with the SL-B9 protected lithium-ion battery pack.Specifications and Features: Protected lithium-ion rechargeable battery pack 3.6V, 850mAh with on-board safety control circuit, rechargeable up to 300 times Integrated USB-C charge port Charges in 2.5 hours Charge status indicator built into the top of the battery Red: Charging // Green: Charged