This valve is designed to replace the POA valve, converting the air-conditioning system from a pressure by-pass system to a clutch cycling system used on most modern cars & trucks.
It mounts to the outlet (top) fitting of the evaporator. It's purpose is to keep the evaporator from freezing up, which it does by cycling the compressor off when pressures indicate the evaporator is too cold.
Can be used for all refrigerants. Ideally recommended for cars where the compressor has been converted to a modern compressor but will still work with original style compressors.
For GM Models: Not for use on early 1965 models that used a Suction Throttling Valve (STV) or late 1974 models equipped with a VIR.
For Ford Models: If your valve has two small lines attached to the side, this valve will work. If your valve has only one small line, you can still use this valve, but a GM Expansion Valve must be purchased as well.