Steel, used to lock the wheels . Name :Wheel lock , Wheel clamp, Wheel klamp,Tyre lock Model :CAS-CLS-5 Name :Wheel ... lock , Wheel clamp, Wheel klamp,Tyre lockModel :CAS-CLS-5Spec. dia.1200Width380mm,thickness2 ... can be used in parking lots and any other places for car stopping . Steel Wheel Clamp/Parking/Car Lock