The 
NUPROL 1150mAh 11.1v 20c LiPo Battery
 is a compact, high-voltage lithium polymer battery designed primarily for airsoft electric guns (AEGs) with small battery compartments, such as stock buffer tubes. It features a stick configuration and a Small Tamiya connector. 
 
Key Specifications
According to the manufacturer and various retailers, the 
NUPROL Power 11.1v 1150mAh LiPo Stick battery
 has the following specifications: 
Type: LiPo – Lithium Polymer
Capacity: 1150mAh
Voltage: 11.1v (3S)
Continuous Discharge Rate: 20C (at 23A)
Burst Discharge Rate: 40C (at 46A)
Configuration: Stick
Connector: Small Tamiya