A-B1B493537S-AI FILTER-A/C FOAMOne New Aftermarket Replacement A C Foam Pre Cleaner Filter Fits Briggs & Fits Stratton Small Engines This flat panel foam pre cleaner filter installs in front of the paper air filter cartridge on select Fits Briggs & Fits Stratton (B&S) small engines, adding a second layer of protection against airborne dirt particle ingestion. Used on select 3. 5 HP to 6. 5 HP Quantum series engines, it helps extend engine life and maintain clean airflow to the