The HD Spindle bearings are Engineered to provide Maximum Performance for the Most Demanding Applications. HD Switch Spindle Bearings are Built with C3 Clearances Designed Specifically for Mower Spindle Applications. The C3 Clearances combined with High Temperature Grease reduces Friction. The Result is a Cooler Operating Temperature and Extend Bearing Life. Our High Temperature Specialty Grease, C3 Clearances and World Class Quality Make The HD Switch a Best in Class Option.