Simply put, an AEG airsoft gun is powered by an on-board Ni-Cad battery similar to the battery used in hobby R/C Cars. The battery-powered motor turns gears inside the gun to compress and release a piston, creating the blast of air needed to propel the 6mm BB through the gun"s barrel. This system allows the gun to generate the power needed to support the fully-automatic features of most AEG airsoft rifles. The result of this automatic airsoft rifle is the delivery of a rate-of-fire (ROF) from 600 to 900 rounds-per-minute (RPM), mimicking the capabilities of real steel firearms.