Add expedition style side rails to the Front Runner Slimline II Roof Rack at any time. This side rail kit allows the front and back of the rack to remain open for loading larger items onto the Slimline II Roof Rack (eg. Canoe/Kayak, Surf Board, Lumber) or for mounting certain accessories at the edge of the rack, like the Front Runner Double Jerry Can Holder. Please Note: This kit only works with 11 Slat-long Front Runner Slimline II Roof Racks. Install in minutes. No drilling required. Adds extra cargo support. Attractive, low profile design. Mounting hardware included. Powder coated with the same durable, weather resistant finish as the Slimline II Roof Rack. Manufactured with corrosion resistant, high-density aluminum components. The Expedition Rails add 61mm / 2.4 to the height of the roof rack. The modular bolt on design allows you to remove rail components whenever needed, ie. to mount a roof top tent off the side.