I believe that it is very much like a Nightmare. So the top tube will hold 15ish paintballs, with the back portion (Behind the hole that links to two tubes) holding a 12 gram. Looking at VR, there is a pistol, the same as this but shorter barrel, and another one that looks much like this, but with a Crossman stock, CA adapter, and a pump handle that is long and has holes in it for most likely weight reduction.
Looks cool. If anything, I love the roundness of the Nightmare bodies, but either this or a new Nightmare would be cool.