<p>R-12 to R-134a conversion adapter for the discharge / high side of an A/C system. This adapter fits the smaller of the two discharge ports, the size of this adapter is 3/8″. The adapter includes a new valve core which requires the removal of the original valve core. <br />There are two different Discharge adapters sizes. The R-12 suction port is 7/16″ if you need a reference try the low side port cap on the high side. If it fits it is a 7/16″ port then select part number V332. If it does not fit this is the correct adapter.</p>