Features: This valve features high temperature , , reliably sealing. Remove excess air during the of the exhaust system and hvac system The exhaust mechanism is very and is cast from high-precision components It is convenient to demount and maintenance, while the water in the system will not out, so there is no need to empty the system. The steam 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. It can 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: brass Thread size: DN25 G1 Length:7cm/2.8in Width:4.8cm/1.9in Weight:Approx.161g/5.7oz Package list: 1 x Brass Automatic Air Vent valve