Resolved what is this part?

[jimsgsx]

I think this is the fpr solenoid. Im pretty sure of it. But what is the little handle knob thing on the right. I can turn it either way but don't really want to mess with it until i understand what it does. Can someone explain this to me please. Thanks.

 

[synthetek]

Its an fpr solenoid. That's not a knob its a vent, that's just a cap on it turning it doesn't do anything.

 

[jimsgsx]

Ok. Thank you for the information.