Good stock for mil-spec buffer tubes, but won't fit non-mil-spec airsoft stocks if they aren't thick enough for it to tightly clamp onto.
This does improve recoil well. It feels how it should have, as standard recoil is kinda rubbish
But.
With gas mags it does cause random issues mainly random auto fire and because of the heavier mass it can struggle with bolt lock back if it’s cold
On hpa this thing is wicked though
Good looking markings. Ejection port looks cheap, on mine it have some weird bulge. On my model there is no top cut for outer barrel, unlike on picture on website.
You get a better quality valve as the one you can find in the original well mags. You also get the spring, the slicone orings and the copper gasket.
I have no way of filing it down. The pieces won’t fit there too big it was said that it was compatible, but it’s not I’d like my money back.