1/2" 3/4" 1" BSP Male Thread 304 Stainless Steel Automatic Air Pressure Vent Valve Safety Release Valve Pressure Relief Valve
https://www.vogueparade.com/shopping/EN/200282142/1/1005002603957358/12-34-1-bsp-male-thread-304-stainless-steel-automatic-air-pressure-vent-valve-safety-release-valve-pressure-relief-valve//