Keep recovery and recycling units operating at peak efficiency with a convenient maintenance kit. Contains one quick change filter-drier to be used on both R-12 and R-134a stations, and one 16 ounce bottle of our Premium High Vacuum Pump Oil. For models using 34724 Filter-Drier (17700A, 17700-2K, 34700, 34700-2K, 34800, 34800-2K, 34900 Series). See your instruction manual if you have questions about which filter-drier to use.