Bookcase features a strong steel exterior, shelf construction, and solid fiberboard back, Plastic, snap-in radius corners make assembly easy and add to the overall strength, Shelves, except the bottom one, adjust at 1"" increments during assembly, Generous 12"" deep steel shelves accommodate three-ring binders and large publications, Fixed bottom is counted as a shelf, Bookcase is made of 50 percent recycled material, SKU: SPRCH27729