... 1/4 3/8 1/2plug for radiator installation, with NBR O-RingHeating Line use Air Release Valve1. Working pressure 16 bar2 ... body nickle plated, or brass finish4. Plastic switch (ABS)5. Release: M6, M8, M10, NBR O ring sealing,6. Pipe thread ... :copper 3.size:3/8", 1/2", 3/4", suitable for general water service 4.we also offer OEM service 5 ... and do our best to serve you Radiator Accessory Air Release Valve