RH665 is not the same as other racing brake fluids, it has been specially formulated for racing applications, where braking systems operate at very high temperatures. It is a complex mixture of glycole ether borate esters and polyalkylene glycol together with advanced corrosion inhibitors, antioxidants, and other modifiers. The result is an exceptional brake fluid with not only a very high boiling point but which also conforms to FMVSS 116 DOT 4 and maintains its class leading viscosity, lubricity, and compressibility performance at extreme temperatures to ensure braking system reliability and performance and a rock hard pedal.