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. ... dia.780Width280mm,thickness2.0mm 780X280X2.0mm Material: high quality steel pipe, high pressure . Function : Lock the wheel ... and any other places for car stopping . Steel Wheel Clamp/Parking/Car Lock