Item Name: Gear Ceramic Ball Bearings Deep Groove Ball Reel Bearing Bearing RS SMR105. Description Bearing Type: Deep Groove BallAperture (D): 5MMInner and outer ring material: 440C stainless steelLubrication: Grease freeHardness: 58HRCBearing class: ABEC-7 Standard clearance: COCap: rubber sealBearing model: SMR105 2RS CBBall Material: Ceramic S13N4Width (B): 4MMOuter diameter (D): 10MMfeature:1. Mixed material stainless steel SUS440 + silicon nitride ceramic S13N4, the mixed design is dedicated to high speed.2. The surface is smooth and textured, the hardness and wear resistance are uniform, and the service life is long.3. The bearing has good performance, uniform speed during operation, low noise, and high efficiency when it cooperates with the machine. Package Included:1pc ceramic ball bearing notes:1. Due to different displays and lighting effects, the actual color of the item may be slightly different from the color shown on the picture.2. Due to manual measurement, please allow 1-5mm measurement deviation.