Combining the best of value and performance, Stens air filters block dust, pollen, dirt, insects and other contaminants from entering the engine, while also allowing sufficient amounts of air to flow through the system. For best operation, your engine needs to be free of all of those contaminants, but it needs air flow to allow the internal combustion engine to work at maximum efficiency. As a recognized name in the outdoor power equipment industry, Stens has earned a reputation for producing best-of-class quality air filters. Owners of outdoor power equipment can expect enhanced performance, reduced engine wear and efficient operation of their machines equipped with a Stens air filter. Thanks to Stens exact-fit design, every air filter is made to match the original air filter used in outdoor power equipment. A perfect fit ensures high-level protection for the engine and simple installation of the filter. Air filters should be replaced on a regular schedule or sooner if environmental conditions require it.