Upgrade your 412 Folding Bicycle with this durable Bicycle 9T 12mm Refit Single Speed Cog Sprocket from Qcwwy. Crafted from reliable material, it offers high strength and wear resistance for long-term use. Experience smooth riding with fast speed and effortless pedaling. The precision threading ensures a secure connection to the drum for minimal noise. Ideal for bike repair or refit, this freewheel guarantees your bike’s proper function. Enjoy a simple setup with easy installation, no complex steps needed.