Maximize your rifles full potential and upgrade your AEG with this Version 2 Complete Gearbox Kit from E&L Airsoft. Low resistance wiring through this gearbox provides exceptional trigger response while protecting trigger contacts and can operate on even the most powerful LiPO batteries. The integrated Quick Change Spring System allows players to easily switch out the internal spring to alter overall velocity and RPM. Four 7mm bearings and two steel bushings ensure rapid and smooth gear changes, putting less stress on the gearbox itself greatly improving battery consumption. This gearbox is reinforced in key areas with upgraded stock internals to provide optimal reliability and durability. An upgraded high density polymer piston and high compression cylinder head provide increased pressure within the rifle for exceptional performance. E&L Airsoft provides everything you need to focus on the battle at hand and secure the win.