850-208M

Air Valve has a single 4mm hose fitting and is used with a compressor

865-208M

Air Valve has a single 6mm hose fitting and is used with a compressor

850-208MK

Air Valve has double 4mm hose fitting and is used with a compressor

850-207U

Air Valve has a double 6mm hose fitting and is used without a compressor

850-207

Air Valve has a 4mm and 6mm hose fitting and is used without a compressor