at Home Depot that goes to sinks or something like that. Got it from the plumbing dept. Each piece fit over the STB and I epoxied them onto the panels where they were cut. They are rubber and easily painted, I did a flat black that matched the interior panels. I must confess I'm not real good at fabricating stuff but it came out looking like it belonged their. I did this with Stillen RSTB but I'm sure it will work with the Carbing or other brands out there. Washers were about $2 apiece, there kinda thick..............