Brake fluid CASTROL React Performance DOT 4 1L. It is a synthetic brake fluid with high boiling point that far exceeds the technical requirements set by SAE J1704, FMVSS 116 DOT 3 and DOT 4, ISO 4925 and JIS K2233. This product has been manufactured with a polyalkaline blend of glycol ethers and boron esters, together with other high performance additives and inhibitors that give essential protection against the effects of corrosion and blockage of the system by the formation of bubbles due to high temperatures.