Made by durable thick carbon steel, also painted by ecological black paint, heat resistant and anti-rust. This microwave shelf rack is suitable for your kitchen, and any other storage areas such as shower room, wardrobe, garage, etc. It comes with 4 bonus hooks ,1 Cutting Boards Stand,1 towel rack ,you can store oven mitts, kitchen utensils, or hand towels. The length of this microwave kitchen shelves is expandable from 17.4″-27.4″. There are also small holes in different height thus you can adjust the rack height through different hole when you install it. Adjust its size according your needs to easily store a microwave oven or other kitchen appliances, save more space.