Keep your engine running clean with a replacement air filter (697152, 697775, 613022, 698413) for Briggs & Stratton 21B900 series engines. This filter fits Briggs & Stratton's 21A902, 21A907, 21A977, 21B902, 21B906, 21B907, 21B972, 21B976 and 21B977 10 to 13 Hp gasoline engines.