This is the Traxxas Series 4 7 Cell High Voltage NiMH Hump Pack. FEATURES: High voltage, high current Traxxas high current connector with 12 gauge wire Series 4 power cells INCLUDES: One 7 Cell NiMH Hump Battery Pack REQUIRES: Peak-detection charger SPECS: Length: 140mm (5.5") Width: 48mm (1.9") Height: 45mm (1.8") Charge Rate: 3A COMMENTS: mAh rating not given by manufacturer cnh 9/23/09 ir/jxs