SPECTRO Heavy Duty DOT 5 Brake FluidDOT5 Silicone Brake Fluid Heavy Duty. Designed to surpass all DOT 5 specifications and requirements, Spectro's Heavy Duty DOT 5 is the ideal brake fluid for all Harley Davidson motorcycles specifying a DOT 5 fluid. But its better, because this fluid beats spec in every way. It meets full OEM requirements, and should be used according to manufacturers instructions. Surpasses DOT 5 specifications Non hygroscopic, it will not absorb water Will not harm