The Snap-on Filter Dryer Kit, No. EAK0030C01AB, is designed for use on virtually all A/C service units, such as early R12 models and later R-134a models. The kit includes a filter and instructions. The kit is for EEAC301B, EEAC304D, EEAC313A (R12 side), EEAC316A, EEAC318A, EEAC319A, and EEAC320A to help keep running at maximum efficiency.