This simple cap can be used to block off the EGR (exhaust gas recirculation) fitting on the Racing Beat (or comparable) header for racing applications. This fitting can be used on the "male" EGR fitting on a 1994-97 or 2001-05 Miata header. (We do not offer a fitting for the female fitting on the 1999-00 Miata application.) *In California this product is only for racing vehicles, which may never be used upon a highway.