You obviously are not well aware of following links. I wansnt talking about a slip mount collector that you buy. This is a plate of 1/8th steel with holes cut in it for the primaries to slide through. The fit is close it takes a mallet to get them through when cold but they will allow for expansion. FWIW they do get run on the street in Allens SVO EVERY day and they make a little bit of sound when cold but after a minute are quiet and there is VERY LITTLE carbon tracking on the collector (probably from when cold) Just cause HKS doesnt make something doesnt mean its junk