Item: MR148 CE Ball Bearing Type: Full Ceramic Ball Bearing Cage: PTFE Balls: ZrO2 zirconium oxide ceramic Inner/outer races: ZrO2 (zirconium oxide) Ceramic Dimensions: 8mm x 14mm x 4mm/Metric ID (inner diameter)/Bore: 8mm OD (outer diameter): 14mm Width/Height/thickness: 4mm Size: 8x14x4 mm Quantity: One Bearing