Small Rear Wheel Hubs for Scooter 1,meterial:aluminium alloy 2,size:17mm/22mm 3,customer-made acceptable 4, free sample Specification: MaterialAluminium ... ,size:17mm/22mm3,customer-made acceptable4, free sample, you just pay for the freight5, used for scooter, motorbike, bike, tricycle,segway etc ...