Strong steel exterior and shelf construction together with solid fiberboard back make these bookcases the best value on the market today. Attractive, plastic snap-in radius corners make assembly easy and add to the overall strength of these units. Shelves adjust at 1" intervals during assembly. In addition to fixed top and bottom shelves, models 7172, 7173, and 7174 contain one additional fixed shelf. Bookcases are 31 3/4"W x 13 1/2"D. Generous 11 3/4" deep shelves accommodate 3-ring binders and large publications. Fixed bottom is counted as a shelf. Choice of printed steel in medium oak or baked enamel finishes in black, gray, or sand. Easy assembly with push-in fasteners.