||This is a great piston. But it took a little work to make it work.
It has it's ups and downs. So I'll just do the old pros and cons trick
Great for high speed gear boxes
Ball bearings for increased spring life and efficiency
Now for the cons... There was only one issue with the piston head
It has a very small screw That holds the bearings and the piston head to the
Piston. Well it's a metal screw into polycarb. This added with the ball bearings means
It came undone because the screw came loose, and stripped my gears because my spring could
Not compress due to the bearings falling out of place, This head is not made for an m120 spring without modification because of such a good air seal which creates alot of pressure. I fixed it with a bigger and longer screw and fired over 10,000 rounds so far no Problems. But it's a great piston for the little extra cash. I recommend installing by experienced players only though, otherwise you may experience major frustration like I did.