The multiple-tier shelves are made of selected materials, sturdy steel, and durable CARB P2-compliant MDF boards. The storage shelf features an adjustable height and dividable structure. The structure of the shelves can be changed to meet your various needs. In addition, the galvanized surface of the racks is rustproof and smooth enough to prevent scratches and damage. Provide a long-term service life for you. It is hassle-free to install the storage shelves at all. You just need to connect the beams using the included steel connection pieces without bolts, and then put the MDF boards on.