METALTM 4400 - Whether you"re sprinting the long expanse between airline gates under a tight connection, or relaxing on the train for your commute home from the daily grind, Brunton"s Metal 4400 will keep your phone or music churning. Its sleek exterior will accompany your briefcase and business suit or skinny jeans and sneakers. POLYMER BATTERY 4400mAh POWER OUTPUT - 2.1 Amp & 1 Amp SPECS - 1.7 X 5.3 X 2.5 cm; 206g INPUT - INTEGRATED USB OUTPUT - DUAL OUTPUT - USB 2.0 + MICRO USB.