Add-on Unit is designed to expand Lorell Industrial Wire Shelving Starter Kits (sold separately) and organize your storage areas. Kit includes four 48" wide x 18" deep shelves and two posts. Easy collar-and-sleeve assembly requires no tools. Each shelf adjusts in 1" increments. Shelving is made of steel with a powder-coat finish, 10-gauge shelf surface, 3-gauge frame, and 6-gauge wave pattern.