Hoffman 401455, Model 41 Convector Steam Vent, 1/8" NPT Air Valve (non-vacuum). Single non-adjustable port. For small steam systems. Telescopic siphon tube with angle cut assures drainage. 1⁄8" NPT straight shank. Maximum operating pressure 6 psig (0.4 bar). Maximum pressure 10 psig (0.7 bar).