Feature: 1. Hardening Technology: The flywheel adopts hardening technology, with greater wear resistance, durability, high temperature resistance, corrosion resistance, rust prevention, no deformation, high durability and good impact resistance. 2. Strong Compatibility: The high accuracy of the bicycle freewheel tooth shape, toothless design and strong compatibility make riding more possible. 3. Hollowed: Reduce the riding load, achieve a good balance between strength and weight, and is easy to install and use. It is an ideal choice to reduce the weight of bicycles. 4. Easy to Install: This flywheel is easy to install, professional manufacturing, direct replacement of old or damaged flywheel, excellent accessories for mountain bikes and road bikes. 5. 10 Speed: Bicycle flywheel is made of high strength steel, 10 speed, number of teeth are 11 13 15 17 19 21 24 28 32 36T. Specification: Item Type: Bicycle Freewheel Material: High strength steel Gross Weight: 720g/25.4oz Speed: 10 Number of 10 Speed Teeth: 11-13-15-17-19-21-24-28-32-36T. Package List: 1 x Bicycle Freewheel