Tenergy LiPO 11.1V 1400mAh 20C Long Stick Battery Pack for Airsoft Li-Polymer batteries are the newest available batteries for airsoft and other hobby toys Dimension: 170mm x 20mm x 18mm Recommended Fit: Folding Stock AK Series, UMG, MP5k, MP5 PDW This 11.1v Li-Po battery can deliver more power than 12v Ni-MH large type battery with only half of the size and a third of the battery cells. They are designed as a light weight, high output power source.