High performance DOT 5.1 brake fluid designed specifically for mountain bike disc brakes The formula created provides maximum fluid life to ensure the best braking performance is maintained for as long as possible DOT 5.1 is 100% compatible with systems that run DOT 3 & DOT 4, & comfortably exceed their performance specifications A full replacement of oil is recommended if upgrading from DOT 3 or DOT 4 oil Ultra low-viscosity oil provides excellent operation even in the most extreme riding conditions Whatever the weather, brakes filled with Finish Line brake fluid will stop you on a dime