K&N RX-3900-1 Universal X-Stream Clamp-On Air Filter: Round Tapered; 3 in (76 mm) Flange ID; 4.625 in (117 mm) Height; 4.5 in (114 mm) Base; 6 in (152 mm) Top Pleated filter built in top Washable and reusable Low restriction Clamp-on design