Prepare your semi to be Ready for the Road Ahead™, with the Donaldson Diesel Exhaust Filter Cartridge that provides clean diesel exhaust fluid. To remove contaminants from the DEF solution so that the selective catalytical reduction system can perform at optimal levels, this replacement filter is crafted with a specialized design. Fashioned with a durable and long-lasting design to reduce the frequency of change intervals. FleetPride is your First Click in Heavy Duty®.