I've been using OR3GUN's stuff pretty much since it first came out. Love the parts they sell. I even was lucky enough to get to test some of the parts out before they were released. (I was having some of the issues that the parts were designed to fix)
Custom MST (Marine Spacer Tube). Mine is NiB coated.
Custom CSP (Competition Spring Plunger). Also NiB coated.
EBR (Enhanced Bolt Release)
And I have the forearm retainer on order from them.
I used to run the follower as well. but it doesn't work with the XRail I now have. The custom coated parts I ordered from them raw with no finish, and had my coatings guy coat them for me. great bunch of guys.