... CSTBAT adiator plug size 1/4 3/8 1/2plug for radiator installation, with NBR O-RingHeating Line use Air Release ... -20+150C3. CuZn39Pb3 brass body nickle plated, or brass finish4. Plastic switch (ABS)5. Release: M6, M8, M10, NBR O ... .size:3/8", 1/2", 3/4", suitable for general water service 4.we also offer OEM service 5 ... price and do our best to serve you radiator accessories Mount&plug kits for radiator