A-B1271939-AI FILTER-PRE CLEANEROne New Aftermarket Replacement Filter Pre Cleaner Fits Briggs and Stratton (B&S) Small Engines This wrap style foam pre cleaner wraps around the main air filter cartridge to provide a first stage of filtration, catching large particles of dirt, dust, and debris before they reach the primary filter element. Designed for use on select Fits Briggs and Stratton 17, 19, and 25 cubic inch horizontal engines commonly found in lawn and garden equipment.