Full gear sets contain: The Gears, a piston, and a set of bushings, the other "gearsets" only include the gears. Helical gear sets have a larger surface area that "flat" gearsets, and thus disperse the torque better. This results in less stress on your gears, and can extend gearbox life. Best used with Systema pistons. Recommended for experienced or Professional Repair/Upgrade technicians.

Not Compatible with Tokyo Marui M14 style airsoft rifles.

**Product my vary from image