These covered bearings have a smooth urethane or neoprene surface that is cast to the precision sealed ball bearing. They provide smooth, quiet and non-marring operation. The urethane provides excellent abrasion resistance and durability. Neoprene provides flame and weather resistance. Covered bearings are available with hardness ranging from 35 to 95 durometer. They come assembled with a button head cap screw, spacer and locknut for fast easy mounting.