4th gen bm2k, nitroduck mega reg, gas thru, eclipse bolt, stock lpr, vapor valve
If the venturi bolt fits your gun, the venturi bolt is a great product. I know it won't fit my buddies 2nd gen. I have no idea why. It's a duplicate of the style of bolt that comes stock in the Angel, and along with a vapor valve it will quiet your gun until an Angel is loud by comparison. You won't be able to hear it shoot. With the valve change my gun shoots 285 fps at about 160 psi. Efficiency is just like the same style of bolt works in the Angel--good.
Questionable fit on older guns. Hi price. Is it worth 50 bones? Depends. If you want that Angel sound and efficency, get one before they go out of production like the Wetworx. The 2nd bolt that comes with the set is just like the other reviewers said---useless.
It's a very good product if it fits. Blowback on my gun is zero. BM2k owners, support the aftermarket, or it won't support us.