air vent valve 1.> material:brass 2.> size: 1/2",3/4",3/8" 3.> working temperature: < 100 degree 4.>working pressure:3 bar Avonflow Baiyilun TRV Co.,Ltd.specialized in the manufacture of thermostatic radiator valve.We have produced this kind of products for ten years and got a lot of experience.Since now ,we have exported our good to over 30 countries such as Russia,Romania, Greece,Croatia,Turkey ...