Its a Hobbs switch, but it only has one wire out. I figure that it sends out a ground when it see boost. I open the back and there is an allen screw. Does anyone know if its adjustable? Im hooking up a water injection kit, and I wanted to see if I can use that pressure switch.

Most pressure switch from Hobbs comes with two terminal. I know that it closes when it sees boost thus connecting the two terminal together. How does the one from JRSC kit work? Does it depend on the ground of the body of the manifold, so when it sees boost it just connects to the manifold which trows out a ground?