Boat Motor Water Pump Impeller 47-85089-3 47-85089-10 18-3057 for Mercury Mariner Chrysler Force 18HP 20HP 25HP 30HP 40HP 45HP 50HP 75HP outboard motors Number of Blades: 6, Brass Hub Height: 12.21mm External Impeller Overall Diameter: 73.39mm Internal Shaft Insert Diameter: 15.98mm Net Weight: 40g