Heavy-duty, weatherproof with a five-roller clutch means that you can use this starter drive Bendix gear assembly for year with trouble-free service. Fits 1965-1988 Harley FX/FL Big Twin Touring, Softail, FXR & 1967-1980 Sportster 900cc/1000cc/1200cc Models Dimensions: 12mm ID x 42.5mm OD x 41mm L Replaces HD# 31443-65A