USB Rechargeable Battery Pack, it serves as a portable charger for small USB devices such as your phone or cyclometer/GPS. 

7.2V 7Ah USB battery pack. Compatible with ALL Magicshine bike lights with Round Plug. for MJ906 and Monteer 5000S

Operating temperature 14-104F Discharge temperature 50-104F

Size:42x30x188mm Weight:287g

The battery is more ergonomic and straps neatly to your frame using nylon straps

The new waterproof battery compartment design and high quality and large area silicone non-slip mat

All Magicshine batteries include a circuit with over-charge, over-discharge and short circuit protection meaning you can be sure that your Magicshine battery is safe to use and charge.