This is an essential part to connect your mechanical oil pressure gauge to the rubber hose in the engine bay. This has to be leak proof or you will spill oil on your thigh (ask me how I know). This screws onto the back of your gauge, runs through the firewall, and plugs into the rubber hose that comes off the block fitting.
If you have any doubts about the fitting or hose, get the complete line kit, which will include everything.
