PB-4000 Zoom energy torus. The Zoom® Energy Torus allows you to customise your powerbank. This set includes black, lime and turquoise silicone cases to match your personality or mood. This 5V/1A 4000mAh Lithium Polymer battery backup will charge your smartphone at the same rate as a wall charger. The slits on the back of the silicone case double as cable storage. Includes a USB to Micro USB charging cable which can charge the battery backup or charge up other devices with a Micro USB input. Metal and Silicone. 118.