Spektrum SPMB2000LITX 1S 3.7V 2000mAh Transmitter Battery for NX6 and NX8 

This is a replacement Spektrum RC 7.4V 2000mAh Transmitter Battery, intended for use on many of the Spektrum Transmitters in both air and ground categories. Radios such as the DX9, DX8, DX5 Pro, and many more.