you will need two sender units, one to measure oil pressure and one to measure oil temp, these screw into the engine, the pressure one goes instead of the original oil pressure switch, and the oil temp instead of the sump plug. Good luck fitting the pressure sender on a zetec-s engine!!! I fitted one on my old 1.6 focus (same enging as in the ZS), and the pressure gauge sender is a lot bigger than the standard oil pressure switch. This meant it fouled a piece sticking out of the block, so i had 6" of oil hose made up, then mounted it up and out of the way behind the inlet manifold!

Rich