Aim gearbox hi speed 8mm for m4 (m150)

New reinforced model available
extreme hi speed with m150 spring
8mm ball bearing
all metal internal parts
wire on front for handguard
to use with highest power and capacity batteries

INTERNAL PARTS INCLUDED 
- steel gear with self adjustable shims and delayer cam 
- steel teeth piston with polycarbonite piston head 
- steel made cylinder head 
- hi pressure aluminum cylinder 
- 8mm steel ball bearing 
- steel spring guide with bearing
- pvc seal nozzle 
- low resistance silver coated wire set