1.High precision,Long life 2.Quick delivery,best after-sale 3. ... Specifications/Special Features:Dimensions: Bore: 1mmOuter bore:1,000mmMaterial: chrome steel, stainless steel, ceramic and plasticType: rubber seal, shield, N, and NRLubricate: grease ... and machinery Single Deep Groove Ball Bearings,Made of Chrome Steel, Ceramic, Plastic and Stainless Steel