Features:This valve features high temperature proof, rustproof, reliably sealing.Remove excess air during the operating of the exhaust system and hvac systemThe exhaust mechanism is very dependable and is cast from high precise componentsItis convenient to demount and maintenance, while the water in the systemwill not flow out, so there is no need to empty the system.Thesteam and water separation tray is designed with special structure to ensure that the water will not be discharged during exhaust.As long as the system has pressure, the exhaust valve will continue to vent.Itcan be operated reliably, either when the system is running with water added or when the system pressure is too high and adequate drainage is required.Specification:Material: brassThread size: DN15 G1/2Length: 7cm/2.8inWidth: 4.8cm/1.9inWeight: Approx.114g/4.0ozPackage list:1 x Brass Automatic Air Vent valve.