Finish Line has two high-performance brake fluids. One is mineral oil-based, and the other is a synthetic DOT 5.1 formula (refer to your brake user guide for the type of oil). Both fluids are designed for use in hydraulic disc brake systems on bicycles to provide maximum fluid lifespan and optimal braking performance. Although they are 100% compatible with DOT 3 and DOT 4 fluids, Finish Line’s DOT 5.1 performance specifications far exceed them. Both fluids use low-viscosity oils to ensure excellent operation even in very cold conditions.