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.
New 102-537 Air Filter For Stihl Hs 81R, Hs 81Rc, Hs 81T, Hs 81Tc, Hs 86R And Hs 86T Hedgetrimmers Owners of outdoor power equipment can expect enhanced performance, reduced engine wear and efficient operation of their machines equipped with a Stens air filter.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.