The Ashwood Stackable Bookshelf by Calico Designs can be used as two 2-shelf units or as a single 4 shelf unit. The durable metal frame is powder coated and combined with an attractive, light wood grain laminate that matches several of our home office desks. (Item 51239, 51240, 51241 and 51250) The 23.5-inch wide open shelves keep your office or art supplies easily accessible. Floor levelers and a rear crossbar add stability with either configuration.