Incredibly, it is actually quite difficult to completely remove salt from cooling systems - even with a good flush with fresh water. Whilst a good flush is OK when you are using the boat daily, it is important to give the cooling system a THOROUGH flush fairly frequently. This is when you use this flush kit combined with SX-50 salt remover. Outboard motors Inboard/stern drives Jet skis All of the engines in these products are made from a die-cast alloy which is very susceptible to salt water corrosion. The exterior of the engines are protected by enamel paint but the interior water cooling galleys are not painted at all (Its impossible to get paint to them). Your only long-term protection from standing salt/salt water deposits sitting in there for months/years at a time is this product. If you value your property you must use this product. It not only removes salt from the galleys, it protects thermostats, impellers, seals etc. This product is totally safe on all surfaces. Easy to set up and use. * Includes hose connectors.