1/8" Male Pipe Thread, Automatic Boiler Air Vent Valve, Provides Automatic Air Venting For Hot & Cold Water Distribution Systems, Manual Vent Feature Provides Tremendous Air Elimination Capability For Fast Venting Of Residential & Commercial Systems, Duo Vent Utilizes A Float To Actuate The Valve Plug, Once Air Is Displaced & The System Pressure Is Sustained The Valve Plug Seals & Prevents Any Water From Escaping The System, Maximum Working Temperature 240 Degrees Fahrenheit, Maximum Working Pressure 150 PSI, Brass Construction, Suitable For Gylcol Systems.