Feature: 1. Iron Material: Flywheel is made of premium iron material, which is oil resistant and has a long service life with reliable and durable performance. 2. Durable Design: With its exquisite craftsmanship, the flywheel is durable and will not deform over time, maintaining its function and performance. 3. Easy to Install: The flywheel with adapter is easy to install, convenient for professional bike mechanics and DIY enthusiasts. 4. Enhance Your Bike Performance: The 25.5‑26mm flywheel adapter and 20T flywheel kit is designed to improve your bike s performance with its premium iron material and reliable durability. 5. Versatile Compatibility: With its size of approximately 25.5‑26mm, this flywheel kit is compatible with a wide range of electric bikes. Specification: Item Type: Freewheel Adapter Kit Material: Iron. Package List: 1 x Freewheel Adapter1 x Freewheel