Castrol SRF is a DOT 4 motor vehicle brake fluid for use in motorsport applications. It is suitable for all disc and drum brake systems used in motor sport with the exception of those for which mineral oil is prescribed. Castrol SRF is a high performance product. It has a typical wet boiling point of 270C (518F), greatly in excess of the DOT 4 minimum requirement of 155C (311F); its typical dry boiling point of 310C (590F) is also outstanding.