The RBC011 Roof Top Bike Carrier comes with a unique front head, which clamps around the roof rack crossbars and then secures by two (2) security screws in the head. The extrusion, on which the rear wheel sits, measures approximately 43 inches long. Its made from strong yet ultra light alloy and comes with a bracket to attach to the roof rack on the under side. The RBC011 bike carrier will fit the Rhino Aero crossbars and includes RKLS Rhino Key Locking Skewer. The key locking skewer allows you to securely key lock your bike to your bike carrier.