Specs Diameters Inner (ID) 12mm; Outer (OD) 32mm; Width 10mm Bearing Material Chrome Steel (GCr15) creates long-life bearings, smooth, and low noise Seal Material Rubber - Preserve grease and prevent impurities from entering. Ultra resistant, high quality ball bearings that can be fitted for several machines This bearing is built to survive the toughest conditions, protecting from early failure and collapse, lowering maintenance costs and replacement frequency. NICHE 519-CBB2247R Single Row, Deep Groove, Ball Bearing Pack of 10