This is the 2S 7.4V 250mAH 20C LiPo Battery for the Flyzone Aircore Principle Trainer, Cathy II, ME-109, and Miss America P-51. FEATURES: Two shrinkwrapped cells with discharge and balance connectors INCLUDES: 2S 7.4V 250mAH 20C LiPo Battery SPECS: Dimensions: 0.79 x 1.3 x 0.55" (20 x 34 x 14mm) Weight: 0.53oz (15g)