Full Steel Teeth Polycarbonate Piston for Airsoft AEG Gearbox by King Arms / Matrix

"I used this piston on my build and it worked great, the gears meshed fine and they seem to be of decent quality.

"recommended an excellent piston for a very durable M130-M160 spring I got it with a spring M130 16: 1 gear ratio and Lonex A1 45,000RPM motor and a 9.6 3200 mAh battery and it works perfectly

"Superb piston. From the look of it before I install it, this item is extremely hard and strong, yet light weight.

Pro:
Smooth polished surface.
Defined and hard full rack of teeth
Very hard

Con:
None so far, will post back if this don't last at least 40,000 rounds.

"Unfortunately mine only lasted 2 skirmishes. I have a M150 spring and 18:1 gear ratio, the pickup tooth snapped clean off and the polycarbonate support isn't strong enough for the high stress build. I'm leaving this as a warning I may have just gotten a bad one it happens, but keep this in the back of your mind.

On the bright side when it wasn't broken, worked great.