Product: 2 Sealed-bearing Single Speed Fixed Gear Hub, is a classic fixed gear bike hub with a minimalist design, raw material is aluminum AL-6061, it can not only reduce the weight of the hub, but also has the characteristics of high strength and corrosion resistance, make the hub longer service life. When you ride, the high strength of this Surly Fixed Hub can ensure a safety riding. We are very confident about our bicycle hub, and it has good reputation in many countries. If you have after-sales questions about our products, please contact us and we will do our best to help.