I'm surprised there was no review for this so after havign one in use for a year I thought it was worth providing some feedback. This went into a mid-FPS build 425FPS and it has held up well after a solid year of use. I combined it with a Magic Box ultra seal double o-ring piston head. This piston is well made and very durable. 2nd tooth was already excluded in the mold.
Roughly comparable to the Magic Box high durability piston bit just a small bit less.
(The Magic Box piston was out of stock at the time but this was a good substitute.)
2nd tooth already removed.
So far so good after a full year of use.
Had to shave down a little bit along the outer edges of the piston just outside of the teeth. The ASGI techs already gave me a heads up about that so it was no biggie. Just a small bit of filing on each side to ensure it didn't rub on the cylinder.
A bit beefy so probably not for any low FPS high speed builds. Not sure if you'd start with something a bit lighter even though you could swiss cheese this.