The Ronstan Low Friction Ring is an essential component for any sailing enthusiast. Designed with a 21mm hole, this ring ensures smooth and efficient line management, reducing friction and wear on your ropes. Made from durable materials, it withstands harsh marine environments while maintaining its performance. Its lightweight design allows for easy installation and versatility in various applications, from sailboats to rigging systems. Upgrade your sailing gear with the RF8090-21 and experience enhanced control and reliability on the water!