For the racer that has chosen the XRP quick disconnect fittings for their plumbing on their hot rod XRP also has this nice knurled fitting cap that slips onto the fitting and allows the racer to snap the clamshell back over the fitting making for a leak free seal and helps keep harmful debris from getting into the fittings that may be installed into vital engine acc.
Caps are made from billet alum. and are anodized a bright color for easy to see identification. Nice thing about this it also keeps the clamshell clamp right where it needs to be and keeps the clamshell clamps from somehow mysteriously becoming lost.