This single bike roof rack is manufactured in steel. The bike sits into a wheel channel & the adjustable clamp fits to the bikes down tube for a secure fastening. Fits to most roof bars. A security locking knob is available as an additional item.Key Features:Two piece V try fits up to 55mm tyres,TUV Tested to DIN Standards,Straps tested to 150 kg.,Powder Coated Anti Rust Treatment,Use with roofbars up to 70mm wide X 55mm,100% Manufactured in Italy..