Hoffman 1B, 1/4" Adjustable Straight Convector Air Valve

Air Valve (non-vacuum) Float-type vent Adjustable port for true proportional venting – 6 port settings from slow (1) to fast (6) Telescopic siphon tube 1⁄4" NPT straight shank Maximum operating pressure 1.5 psig (0.1 bar)(Drop away pressure - maximum pressure against which the vent can open). Maximum pressure 10 psig (0.7 bar)