The 
Nuprol Power 11.1V 1000mAh 20C LiPo AK Slim Stick
 is an airsoft battery with a small Tamiya connector, known for its compact size suitable for AK compartments and buffer tubes, and it offers improved trigger response and rate of fire in compatible airsoft guns. 
 
the specifications for this battery are: 
Type: LiPo (Lithium Polymer)
Voltage (Cell Count): 11.1V (3S)
Capacity: 1000mAh
Constant Discharge Rate: 20C @ 20A
Burst Discharge Rate: 40C @ 40A
Configuration: AK (Slim Stick)
Connector: Small Tamiya
Balance Connector: JST-XH
Dimensions: Approximately 169mm x 15mm x 15mm
Weight: Approximately 70g 
 
Usage and Safety Guidelines
Compatibility: This 11.1V battery should primarily be used with upgraded airsoft platforms that can handle the higher voltage and discharge rate, as it can cause excess wear on stock AEGs.
Charging: Use only a compatible LiPo balance charger.
Safety: Always charge the battery in a fire-retardant charging bag and never leave it unattended while charging.
Storage: For long-term storage, the cells should maintain a voltage of approximately 3.8V per cell.
Maintenance: Disconnect and stop using the battery if it shows signs of swelling or expansion, or if the temperature exceeds 70°C, to prevent fire or explosion risks.