The 
Nuprol Power 11.1V 1200mAh 20C LiPo AK Stick battery
 is a high-performance airsoft battery designed for AK-style replicas and other guns with limited battery space
 
Product Specifications
According to Nuprol's official website and various retailers, the specifications for the 
Nuprol Power 11.1V 1200mAh 20C LiPo AK Stick
 battery are as follows: 
Chemistry: LiPo (Lithium Polymer).
Capacity: 1200mAh.
Voltage: 11.1V (3S cell count).
Continuous Discharge Rate: 20C at 24A.
Burst Discharge Rate: 40C at 48A.
Configuration: AK / Slim Stick.
Dimensions: Approximately 15 x 17 x 185 mm (some sources list slightly different dimensions, such as 19 x 21 x 128 mm, so checking your specific gun's battery compartment is advised).
Weight: 115g.
Connector: Available with either Small Tamiya or Deans (T-Connector) plugs; the balance connector is JST-XH.
Cable Gauge: AWG 16.
 
Usage and Safety Information
Charging: LiPo batteries must only be charged with a specialised LiPo balance charger.
Safety: Always charge and store LiPo batteries in a fire-retardant safe-charging bag and never leave them charging unattended.
Operation: Stop using the battery if the temperature exceeds 70°C or if the cells begin to swell or expand, as failure to comply may result in an explosion or fire.
Discharge: Avoid running the battery completely flat, as this can damage the cells and affect overall capacity.