Especially in higher CFM pumps, debris and liquid can become airborn and pass by the primary and secondary traps and can build up inside the pump causing premature failure or vane sticking.
The Conde Stainless Steel Final Filter is designed to catch debris before it enters the pump. Made entirely of stainless steel and will therefore not add to the problem by rotting. Filter element is easy to change and also made of stainless steel for durability.