Features: 1. Made of premium steel material, anti-corrosion and rustproof, durable in use. 2. High accuracy, stable performance, long service life and high reliability. 3. Double-sided metal shielded design, waterproof and dustproof. 4. Exquisite mechanical design makes little noise when rotating. 5. Fine workmanship, smooth surface, excellent mechanical properties. Specification: Model: 686-ZZ/687-ZZ/688-ZZ/689-ZZ (Optional) Size: 686-ZZ: ID: 6mm, OD: 13mm, Thickness: 5mm 687-ZZ: ID: 7mm, OD: 14mm, Thickness: 5mm 688-ZZ: ID: 8mm, OD: 16mm, Thickness: 5mm 689-ZZ: ID: 9mm, OD: 17mm, Thickness: 5mm Material: Bearing steel Operating characteristic: High speed Rolling element type: Steel ball Column number of rolling element: Single column Raceway type: Deep groove raceway Angle: 15 Sealing cap: Double-sided metal shielded Package list: 10 * Bearings Package List 11. Made of premium steel material, anti-corrosion and rustproof, durable in use. 22. High accuracy, stable performance, long service life and high reliability. 33. Double-sided metal shielded design, waterproof and dustproof. 44. Exquisite mechanical design makes little noise when rotating. 55. Fine workmanship, smooth surface, excellent mechanical properties.