Its quite expensive and you need a dremel to install it.
Comes with extra stuff that you don't really need/want.
$249.95, includes a cold rolled steel magazine floor plate with a parkerized finish, a 4140 steel muzzle adapter with a ½ X 36 thread pitch, and a HDPR polyethylene thermoplastic magazine follower.
Another thing is that the finish does not match the MP40 as it seems parkarized and does not look good IMO. No idea why they did that either.
A pain to have to strip that off on top of everything else and its not clear what it would look like underneath.