Power Strap 4000 Power Bank stylish aluminium power bank with 4000 mAh capacity. Comes with a silicone strap so you can keep your phone and power bank together in one package. A Grade Lithium Polymer battery. Features include built in protection function to stabile the output voltage and prevent over charging or short circuit. Suitable for charging all electronic devices. Includes USB to Micro USB charge cable and user manual.