this is brake fluid...anythig else you put is your master cylinder is just juice. I've tried almost every kind there is over the past 40 years of enduro riding and this is the only one that does not overheat after the first hour of riding, never a squeek or squeel. seems to last longer also...only change once a season..not every ride like with others. THIS IS AN OUTSTANDING PRODUCT!trailking101 (30 Aug 2011, 13:16)