7. 4v 2500mah hump rx lipo uni plug receiver pack hump type chemistry: lipo capacity: 2500 mah voltage: 7. 4v connector: universal balancer: xh sizes length: 55mm width: 31mm height: 31mm weight: 104g with a capacity of 2500mah and a very precisely built semi-soft case these batteries will give you more runtime and more stable voltage throughout the race. The pack is available with the uni plug in a hump layout (nvo1504)