I have two of these pistons - and must say that they are great! Very tough, very durable.
My DMR uses an m140 spring on a high torque motor, and I must say, firing full auto - semi auto with all that spring tension, it is easy to believe that a piston would surely have damage... well this piston shows no sign of wear and tear.
This piston is also good for high speed set ups, I have a G36 that is set up for high speed and it is also showing great promise. Witnessed a p90 at the North Atlantic Airsoft Expo that was shooting 36 bbs a second at 350 fps that was using this piston and showed no signs of damage.
As stated, very strong piston, better than any other piston I have come across.
Nothing I can mention, other than the fact that they always seem to be out of stock here
Rating: [5 of 5 Stars!]