Pack'em Aluminum Roof Rack PK28BR2 Racks - 2 piece bracket set (1 crossbar) - 2x4 Bracket Kit for Enclosed Trailers 2 Piece Bracket Set will make One Crossbar Section Only (lumber not included) Made from extruded aluminum with stainless steel mounting hardware 3 sided 2x4 aluminum pocket for superior strength Maximum load capacity is 100 lbs per crossbar New and Improved Weld for added strength and durability