1/2" x 1 1/8" x 5/16" Plastic Radial With Glass Bearing One Bearing 1/2" x 1 1/8" x 5/16" Plastic Radial With Glass Bearing, Bearing is Polymer Raceways with glass, inner diameter is 1/2" inch, outer diameter is 1 1/8" and width is 5/16" inch.