Wedge-shaped low profile design combines style and function with tapered side walls making it easier to load and unload Wind fairing is included to help airflow over your cargo. Load capacity 150 pounds. Internal dimensions-41 x 39 x 5 inches Accessory crossbars (sold separately) allow you to carry additional equipment or stabilize your cargo. Maximum barspread: 37 inches, Minimum barspread: 20 inches Fits a broad range of vehicles with versatile mounting hardware and includes T-Track mounting for Thule aeroblade and Thule xsporter bars. Roof Rack Material: Aluminum Mounts to all Thule rack systems, round bars and most factory racks (check Thule Buyers guide)