SouthMarine Boat Impeller for Yamaha 8HP 9.9HP 15HP 20HP Outboard Motors 63V-44352-00 63V-44352-00-00 63V-44352-01-00 63V-44352-01 Sierra&nbsp;18-3040 &hellip; A External Impeller Overall Diameter: 52.25mm B Height: 13.86mm C Internal shaft insert Diameter: 12.86mm Plastic Hub Number of Blades: 6