... ; 2) effective after-sale service; 3) 3C ISO AIR VENT VALVE Specificationsair vent valves 1.> material:brass 2.> size: 1/2",3 ... ,Turkey, Poland, Ukraine, England, New Zealand and so on. air vent valves:1. material:brass2. size: 1/2",3/4",3/8 ... "3. manual air vent4.working pressure:3 bar5.working temperature: < 100 ...