Reese Towpower Carbon Forged Ball Mounts offer users greater towing capacity through its innovative one-piece construction providing unequaled quality and performance in a unique weld-free design and quality finish. The Interlock design is a patented hex design which allows for a one-wrench tightening system when combined with a Reese Interlock hitch ball. It makes for installing the hitch ball more efficient, and prevents marring of the hitch ball.