This is the EcoPower 5-Cell NiMH AA SBS-Flat Receiver Battery with a Receiver Connector. This battery features 2000mAh capacity is ideal for use as a rechargeable battery for your transmitter, as well as many other applications. The recommended charge rate for these batteries is 1C for the best battery life and run time.

Specifications:
Chemistry: NiMH
Voltage: 6.0 nominal
Number of Cells: 5
Capacity: 2000mAh
Weight: 136g
Dimensions: 53x72x15mm
Connector Type: Rx
Configuration: SBS-Flat
Max Charge Rate: 1C