CHUCK
It really doesn't unless the angle in the pic is misleading. Valid sent me a picture of the pressure switch and I'm going to have to take another look at mine cause they don't look the same either. My compressor seems to be mounted in a vertical position which has a valve on top that can be pulled with a mounted ring that allows air to escape. Then on the side about halfway down is what I was describing as a knob. That may be the pressure switch, I don't know..
Am going to go take a better look and see if I can get a picture of it.