I believe the earlier reviewer is speaking of the Next Gen pistons made by Magic Box for the TM line of guns with recoil. They are not the same spec and have areas that would cause the piston to strip out in standard gearbox set ups. Either way, I have personally used this piston in two of my own set ups, and many other instances of tech work that I have completed for others. From DSG/ROF builds to high FPS builds, this piston has been the strongest I have seen. In some cases, slight modification has been necessary for proper cycling in the GB, but overall, I have not seen a more durable piston. The Lonex Extreme Toughness Red piston is not as durable as this one and the Magic Box is still lighter than that. While I believe the Lonex Red to be an amazing piston and I highly recommend it, this Magic Box piston takes the cake.
Very Strong - doesn't strip easily or ever from what I have seen
Very Durable - takes high FPS builds without failure
Light weight - can be made lighter while not losing any of its strength
Designed even for tighter gearboxes such as the VFC
Sometimes requires modification - but hey, not all gearboxes are alike.
Pricey, but this is for your higher end builds. It's talents shouldn't be wasted on simple repairs - even though it would strengthen the repair, cheaper options will do just fine.
Don't hesitate to buy this piston for those custom builds.