These metal shelves come with post increment ridges that are numbered to simplify shelf placement. The shelving unit can hold up to 800 pounds per shelf and 2000 pounds per unit. These metal shelves come compatible with one inch diameter round post national brand components. The shelving unit comes complete with four posts, leveler bolts, split sleeves, and four shelves. These metal shelves are created from classic steel giving you terrific excellent durability.