Rectangular washing muffs are essential equipment for your outboard engine, as they maintain its good operation and prevent any corrosion inside the engine. When salt remains in the engine's cooling system, it can cause corrosion that may lead to costly repairs and potential engine damage. Regular washing with fresh water helps extend the life of your outboard engine and prevents corrosion. Tighten the washing muffs over the engine's water intake and use water from your home faucet or marina to rinse the engine of salt, sand, mud, etc. Excellent for running the engine out of the water and making necessary adjustments or maintenance.