Description from Design Within Reach
Cubits can transform easily from a shelf to a cabinet with the addition of the optional doors and backs. The backs keep your stored items from falling behind the unit and enables Cubits to be used as a room divider. Made of the same high-quality polypropylene as the shelves, the backs are sold separately in sets of two and can be added and removed at will.
Materials: Injection-molded polypropylene.