Trakpower LiPo 2S 7.4V 4000mAh 50C Hard Case 4mm Short FEATURES: Optimum power for 1/8 scale glow racing Universal discharge and balancing connectors Ideal for high voltage servos and receivers INCLUDES: TrakPower 2S 7.4V 2400mAh Receiver Flat Battery Pack with Universal Discharge and Balancing Connectors REQUIRES: LiPo compatible charger with balancer such as the Duratrax Onyx 235, (DTXP4235) or the TrakPower VR-1 (TKPP5000)