Features： 1、Nickel Chromium Steel Material: Nickel chromium plated high tensile steel plate, multi layer electroplating anti rust treatment, sturdy and durable. 2、Good Performance: Adopting deficient tooth design, smoother shifting, punching to reduce weight, high accuracy gear ratio and strong compatibility. 3、Hollow Design: 10 speed bicycle cassette adopts hollow technology which can easily reduce weight for a lighter and smoother ride. 4、Steady Rotation: The flywheel rotates smoothly and without noise, ensuring tight connection with the bicycle hub and smooth operation. 5、Applicable Model: 11‑30T 10 speed bike cassette is suitable for road bikes, folding bikes. Exquisite workmanship, beautiful appearance. Specification： Item Type: Bike Cassette Material: Nickel Chromium Steel Color: As Pictures Shown Weight: Approx. 382g / 13.5oz Application: Suitable for Road Bikes, Folding Bikes Speed Ratio: 10 Speed 11-30T 11-12-13-15-17-19-21-23-25-30T Package List： 1 x Flywheel 2 x Tooth Piece 1 x Flywheel Cover