High-quality material: 8 wheels are made of high-strength metal, which is anti-rust, non-deformable, wear-resistant and durable. Meets quality control standards and is reliable to use. Good tool: fast driving and labor-saving. Reliable and suitable for mountain bike cassettes. High performance, reliable performance, easy installation. Excellent performance: High-precision threads a tight connection with the bicycle hub and operation. It can that the chain turns smoothly without too much noise. Good replacement, direct replacement for the old or defective one. Quality Assurance: The bicycle flywheel has undergone quality inspection to safety and reliability. Professional after-sales production, quality standards. Good quality can provide a for your life. Colour:As Shown Material:steel Size:15.5 x 15.5 x 9 cm Package Contents: 1 x bicycle spinning freewheel 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.