Tokyo Marui
The AEGs were developed in Japan and the Japanese company Tokyo Marui is credited with creating the original gearbox system. In a Tokyo Marui AEG, the motor drives a train of three gears mounted inside a gearbox, which then loads a pump piston against a spring. Once the spring is released, it pushes the piston plunger forward through the pump cylinder to propel a pellet resting within the chamber forward through the barrel and out of the muzzle. Many manufacturers have now more or less replicated this basic model, adding reinforced parts or minor improvements.