Resiliant EPDM material absorbs shock and extends life of dock lines.These snubbers of resilient EPDM rubber material absorb shock and will help extend the life of your dock lines while minimizing stress to structural areas around cleats caused by the jolting action of wind, waves and wakes. Easy to install and they grip dock lines securely without weakening the dock lines themselves.Choose from three sizes to fit 3/8", 5/8" or 3/4" diameter dock lines.