Modify MODULAR steel gear set with support+piston for 7mm gearbox (15.05:1) Hi Speed

Newest tempered steel set with bearing support installed + light piston
hi quality nano class threatment process
super low friction and noise reduction
max rotation with incredible energy save
light piston with 7 wear-resistant steel alloy teeth
ideal to use with max 110 spring

included parts:
-light piston
-steel gears
-bearing support
-7mm bearing
-antireversal lever
-lube oil

fits g&g,ka,marui type gearbox for m16/g3/ak guns etc....