Area 1000 by Systema original oiless bushings for airsoft AEG version 2 and 3 gearboxes. These can be used to replace Tokyo Marui (or TM compatible brands Classic Army, ICS etc) nylon bushings for seating the upgrade gears. Metal bushings are less likely to deform under stress which increases the life of AEG gears. The bushing diameter is 6mm and flange diameter is 8mm. Compatible with most main AEG types with TM style gearboxes such as M16/M4, MP5, G3, AK.