The large quantity allows you to replace broken or old bearings at any time. And the small size and light weight make you very convenient to carry it. High-quality and standard workmanship makes it have low noise and high torque. The sealing rubber design makes it possible to avoid the entry of contaminants. Made of bearing steel material, it is very durable to use. The inner diameter is 3cm, the outer diameter is 4.7cm and the thickness is 0.9cm. It is very suitable for small hobby 30mm shaft or pole projects. Item Name: Bearing Material: Bearing Steel Model: 6906-2RS Quantity: 10Pcs Color: Silver Color Rolling Body: Single Row Type: Deep Groove High Speed Features: Thin Section, Miniature, Accessories Size Details: Size: Inner Diameter: 3cm/1.18", Outer Diameter: 4.7cm/1.85", Thickness: 0.9cm/0.35" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 10 x Bearings