This is an excellent piston, especially for the price! The construction is solid and very well done, I did not have to clean any burrs, and the diameter is perfectly true (perfectly round, no slight wobble when rolled on a perfect flat surface). I have an ASG AW.308 (Type 96 variant), and it would not work with the stock trigger. This piston is for a 90 degree trigger sear, and many stock triggers have 45 degree sears. I was aware of this when purchased, and I have a 90 degree sear. There are two ways to check your trigger sear style: if using stock piston AND stock trigger, remove the piston and look at the end that the spring goes into (silver end in the picture), there will be a 45deg bevel on the very end, before that bevel will be either an opposite 45 deg bevel or a 90 deg edge. 45 deg bevel should mean your stock trigger sear is a 45 deg sear, a 90 deg edge should mean that you have a 90deg sear. The other way is to look at the actual trigger sear you are running (obviously a better method). Remove your trigger unit. There will be a couple of small, movable components on the side that goes up into the cylinder, the front one (smaller) should move back and forth. that is your trigger/piston sear. if it has 45 deg angles on the top, when pointing almost vertical, then it is a 45 deg sear, if it has and almost 90 deg edge facing the rear of the rifle (when the sear is pointing almost vertical), then you have a 90 deg sear.
Very clean (no burrs, etc.)
Nylon style bands (although great), will expand if exposed to heat. This should not be a problem normally though.
Would have been better if sold with a matching spring guide
Rating: [5 of 5 Stars!]