Roughness of: Ra 0.4 Model Number: KFL08 Structure: Linear Shaft Color: Silver Material: Zinc Alloy Size Approx: Inner Diameter 8MM Package Contents: 20 x pcs 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 a little different from the real thing. The measurement allowed error is +/- 1-3 cm.