This is the lowest cost of Lithium Polymer (LiPo) rechargeable battery that we have ever carried, so that it is affordable for students to use in their projects instead of using the disposable 9V battery that cannot be recharged. It is suitable for low power consumption usage such as circuit board, sensors and micro size DC motors. 

User needs to purchase its charges separately to ensure it is charged in a correct way. Recommend getting 2-3 Cell Li-po balance Charger.

Specification:
2 Cell Li-po in series.
Rated Voltage: 7.4V
Fully-charge Voltage: 8.4V
Capacity: 900mAh
Discharge: 15C
Size: 55mm x 29mm x 14mm
Must charge with designated LiPo Battery Charger
Please check the Wikipedia link for more info about Li-Po battery.