Four Seasons 77391 Remanufactured AC Compressor All remanufactured compressors are built using the latest compressor technology available today and using strict remanufacturing processes. Tested for noise ,vibration ,durability,vacuum decay , and pressure decay to insure no leaks and longer life. Contains R-12/R-134a compatible gaskets, o-rings, or seals to properly replace the product Built in a TS16949 certified manufacturing environment to ensure consistent quality that meets or exceeds OE specifications for fit, form, function, and durability