Vetus Bullflex flexible shaft coupling for an excellent alignment of the propeller shaft due to a special centering ring.↵4821125 - 4821430 max engine power at 3600 RPM (1800 shaft RPM with reduction 2:1)↵4821835 - 4821840 max engine power at 3000 RPM (1500 shaft RPM with reduction 2:1)