This sturdy rack is made of galvanized steel and durable board. Its very stable because of the heavy duty construction, so that you don't have to worry about the problem of falling shelves causing injuries. The feet with pads will keep the floor from scratching as well. The height between shelves can be adjusted freely to adapt objects of different heights. Whats more, the racks can be assembled into different combinations to satisfy your different needs. So what are you waiting for? Please choose this 5 tier storage shelve to enlarge your living space. Gymax 5-Tier Storage Rack Garage Shelf With Heavy Duty Metal Frame-Black in Black