Made of Bearing Steel for durability and resistance.This type bearing is Miniature Single Row Deep Groove Ball Bearing,mainly take the radial load as well as moderate axial load.These ball bearing is fitted with two rubber dust seal to prevent ingress of dirt, water and foreign matter.Bearing Features: simple configuration,high speed,hight precision,less coefficient of friction,less vibration and noise,most widely used.Miniature Deep Groove Ball Bearing suitable for all kinds of industrial equipment, -motor,small rotary motor,office equipment and so on.Product Name: Deep Groove Ball BearingMaterial: Bearing SteelColor: Silver ToneModel: 628RSInside Diameter: 8mmOutside Diameter: 24mmThickness: 8mmWeight: 165gPackage Contents:10 pcs x Deep Groove Ball BearingOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.