Our Rubber chair and stool fittings help to reduce slipping, vibration, and noise. Round rubber ferrules are available in diameters from 1/2” (12mm) to 1.1/4” (32mm). Rubber ferrules are great all-rounder ferrules and one of our most popular rubber feet. For heavier applications, we recommend metal washers inside the bottom of the ferrule to prevent the tube from cutting through the rubber.