The 5 Tier Square Shelf is made from tubular steel and plastic resin, giving it excellent strength and long-lasting durability. Combine this item with matching metal storage shelves to create a seamless modular office shelving system! Each of the shelves can be removed to allow for storage of taller items, and the shelf itself can be extended to accommodate nearly any item. The shelf is designed to be assembled without the use of tools, making it easy for anyone to get it set up. Assembly level/degree of difficulty: Easy.