Features Choose from six stylesOverall wheel sizes available…     4″ x 1.5″     5″ x 2″     6″ x 2″     8″ x 2″     10″ x 3″     16″ x 3″Higher load capacity of standard rubber mold-on wheels with semi-steel centers.Start easier with heavy loads with less effort to keep them rolling.Harder tread reduces heat build-up and embedding of foreign materials from floors.