Features closed with 2 metal , one shield from each side, to protect the bearing from dust or any possible contamination. Commonly used for electric motors, wheel bearings, agricultural, conveying and much more. Package Content: 50 x Deep Groove Ball Bearing Only the above package content, other products are not included. Note: Light reflection 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.