HEAVY METALTM 5500 - Designed with the never-slow-down, everyday user in mind, Brunton"s Heavy Metal 5500 has the sleek, urban aesthetics of the Metal 4400, but with greater capacity for even more on-the-go energy. Robust, lightweight and always there when you need it, the Heavy Metal 5500 is perfect for the truly power hungry. LITHIUM POLYMER BATTERY 5500mAh POWER OUTPUT - 2.1 Amp & 1 Amp SPECS - 7.8 X 11.3 X 1.9 cm, 247g INPUT - INTEGRATED USB OUTPUT - DUAL OUTPUT - USB 2.0 + MICRO USB.