This proven corrosion blocking product from Woody Wax will keep the inside of your engine free from corrosion and your cooling system working like new. Most marine engine failures are directly related to saltwater corrosion and cooling system problems. Treat your engine once a month with this Engine Flush to remove scale and salt and keep the internal cooling parts, water pumps, and thermostats lubricated and working properly. Easy to use on outboards, inboards, and PWCs. Kit includes one brass injector, one brass spray nozzle, two 4-oz. engine flush cartridges, and one 4-oz. boat soap cartridge.