So what is this thing? Anyway, I thought I could carefully open it. Like maybe it was clogged or whatever. Not true: and it's cracked now. Anyway the diaphragm seems to send a little pulse of air pressure to a sensor. Also, I sorta repaired it. Another question: there is a flow arrow on the part, but which way is the "flow" so which way should the arrow point? The line that carries the air pressure is purple - I thought it was electrical but it's just a tube. Also , what is that silver thing it would connect to. That hose is shot. It splits off and connects to a second silver thing.