Features: 1. These bearings are made of high quality steel for low noise and long service life. 2. They are double-sided rubber sealed to avoid contaminants entering and save lubricant. 3. This section bearing feel smooth, low noise, long service life. 4. Low frictional resistance and high speed. 5. With Stable characteristics, high reliability. Specification: Condition: 100% Brand New Item Type: Ball Bearings Model: 687-2RS/688-2RS/689-2RS (optional) Model Inner diameter Outer diameter Thickness 687-2RS 7mm / 0.28in 14mm / 0.55in 5mm / 0.2in 688-2RS 8mm / 0.31in 16mm / 0.63in 5mm / 0.2in 689-2RS 9mm / 0.35in 17mm / 0.67in 5mm / 0.2in Cage and Materials: Steel Plate Use Characteristics: High Speed Uses: General Number of Rolling Body Columns: Single Column Raceway Type: Deep Groove Raceway Bearing Material: Bearing Steel Rolling Body Type: Ball Angle: 15 degrees Sealing Cap: Double-sided seal Rolling Body: Steel Ball Package List: 10 * Ball Bearings Note: 1. Please allow slight error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.