These are modular shelving pieces. Powder coated steel. They snap together with double rivets. There are 36" upright sections, and 12", 24", 36" and 48" cross pieces. I do not have the shelves, but they can be cut from plywood. Two 36" uprights can be attached to a crosspiece to go 6' high. You can make 12 x 24, 12 x 36, 12 x 48, 24 x 24, 24 x 36 24 x 48 or 36 x 48.