Need to stop a coolant leak on your Mazda? This is the genuine Mazda OEM thermostat cover gasket you're looking for. The part number is B621-15-173 (also crosses to B62115173). It's a direct replacement, made to the exact factory specifications, so you know it'll fit and seal perfectly. This one gasket fits a crazy long list of Mazda models from the late 80s through early 2000s, including the beloved Miata (MX-5), MPV minivan, 323, 626, Protege, MX-3, MX-6, and the B-Series trucks (B2200/B2600). We're talking model years from about 1990 all the way up to 2003 for some vehicles. It's made from a high-quality, non-asbestos material, and it comes brand new in its Mazda packaging. Replacing this small gasket is a common fix for minor coolant seepage around the thermostat housing. It's an affordable, genuine part that can prevent overheating issues down the road. Comes with a 1-year manufacturer warranty for peace of mind. If your Mazda is dripping coolant from that area, just swap this in during your next thermostat change or cooling system service. Keep your classic Mazda running cool and leak-free!