Expand your vehicle storage space with the SportRack Aero XL Roof Box (A90275). This cargo box with rear opening mounts to vehicle roof crossbars - providing easy, three-side access for loading and unloading from the rear of the vehicle. Compatible with round and square crossbars and most factory racks, this 18 cu. ft. roof box is simple to mount and install, with a Quick Release u-bolt mounting kit included. A central lock system secures the box's contents, with all mounting hardware placed internally to guard against theft.