If you want your hopper to sit as low as possible on your Bushmaster or BKO, look no further. Goldie has done it again with the Vapor No-Rise. It literally puts the hopper directly on top of your gun (I can't get my pull-pin out without rotating the hopper!) While most advantageous for the HALO, it also works well with the EVlution 2. The No-Rise includes 2 o-rings to ensure a snug fit, and it fits the feed neck of my unsanded Egg2 tightly. It feels solid when screwed into the body of the gun, and although the finish is shiny, it still matches my 2k3 body fairly well. The milling is nice, not overdone.
You may need to buy or borrow a strap wrench to get your old feed neck off in order to put this on... but trust me, it'll be worth it. Now you can have the lowest profile possible without a Warp Feed.
Goldie hits another home-run. A well-designed product that does what it's supposed to do.