Extend your bookcase, and maximize your space! Designed to extend a starter unit, this two-sided shelf is built to be an addition and connects to a starter shelf to additional storage. Since this addition connects directly to the starter unit, it saves space and creates one solid, sturdy piece. Features include two adjustable shelves on each side, a five-point support system to provide additional support to prevent shelves from sagging over time, and wire loop dividers to keep your books standing in the upright position and organized. The unit is designed to create a multiple-shelving unit for your library.