Helps make inventory control more efficient. Unique "flow" design uses gravity to slide cartons to front for easy access. Loads from the back to ensure that first inventory in is the first inventory out. Cartons are transported on roller tracks constructed of U-shaped galvanized steel channels with plastic wheels that support 50 lbs./ft. Box guide rails can be adjusted horizontally and beams can be adjusted vertically to accommodate varying carton sizes. Storage shelf levels are adjustable on 1.5" centers for height flexibility. Box guide rails are used between each pair of roller tracks. Additional roller tracks can be added depending upon carton sizes. Each gravity flow storage level includes four pair of roller tracks with five box guide rails and one cross support. Racks include 5/8" thick particle board top storage level that supports up to 1000 lbs. Gray baked enamel finish. Easy assembly.