Create a unique display: Overhead shelves provide for additional storage space and convenient, lightweight display in the space above a shelving fixture. Order rear post uprights that will extend above the unit and add one or more of these 12" (305mm) deep shelves. Shelf has a drop mat design which provides a retaining ledge on all four sides. Same no tool assembly and, 1" (25mm) shelf adjustability as other standard Super Erecta shelves.