i have these in my m16 they make the gun sound super efficient.
i have an m120 with them and they havnt let me down yet.
but i bought another pair because i liked them so much... i tried to put them in my ics special weapons mp5... no dice couldnt even get them in the bushings. im 100% sure i got a lemon but its something to be weary of that
they sound really nice...
4 stars because i got a bad pair
info about my gun:
TM GB shell
Systema cut off lever
Systema anti reversal latch
Systema smooth bore cylinder
Systema oilless bushings and shims
Systema lo-res wiring with Systema MOSFET
Systema energy piston head and cylinder head nozzle
Systema gearbox spring kit
Prometheus hard piston
Prometheus ball bearing spring guide
Prometheus metal hop up
Tenergy 5000 mAh 9.6
and i shoot .25's
handles an m120 easily
you dont need a new piston with this torque up set
got a bad pair from ASGI but they told me id be taken care of
the standard torque version of these gears stripped in 3000 rounds with an m 120 and a magnum (those were from evike)