Includes: (1) Flight Pack, (850mAh, 25C). Requires: Charging and installation in your R/C helicopter or plane. Specifications: 2S 7.4V 20awg JST (BEC). Voltage: 7.4 Capacity: 850mAh. Charge rate: 25. IR Milliohm: 27-54. Discharge Wire Connector: 20awg, JST. Weight: 1.55oz, or 44 grams. Height: 0.63", or 16mm. Lenght: 1.26", or 32mm. Width: 2.25", or 57mm.