Box beam shelf design and double-sided compression clips support heavy loads and assure durability. Ribbed shelves provide additional strength and minimize shelf deflection. Shelves lock in place, but can be easily repositioned in 1" increments. Up to 725-lb. capacity per shelf (based on 36 x 12 shelf evenly distributed.) One Industrial Post Kit (SAF5256), sold separately, must be ordered for each set (carton) of shelves. Six shelves per carton. Dark gray finish. Manufacturer’s limitd lifetime warranty. Assembly required.