Pack'em Aluminum Roof Rack Racks PK28B - 4 Piece Set (to Make 2 Cross Sections) - 2x4 Bracket Kit for Enclosed Trailers 4 Piece Bracket Set to make complete rack as shown in photo (lumber not included) Made from extruded aluminum with stainless steel mounting hardware 3 sided 2x4 aluminum pocket for superior strength Maximum load capacity is 200 lbs New and Improved Weld for added strength and durability