1. plastic rotating head and nickel-plated brass 2. size:1/2",3/4" Manual Air Vent(Radiator Valve)1. plastic rotating head and nickel-plated brass2. size:1/2",3/4"3. manual air pressure reducing4. max.temp.:110degree5. max.pressure: 10 bar(air vent valve, air vent plug) Manual Air Vent(Radiator Valve)