An extra-deep bookcase with an open back. Shelves have a discreet stop at the back, open for easy wiring. The bottom 2 openings are a fixed height, the top 2 shelves are adjustable. DimensionsOverall: 33″ wide x 14″ deep x 72″ high. SKU: 50052 bottom shelf openings: 30″ wide x 13″ deep x 12″ highUpper opening: As large as 30″ wide x 13″ deep x 39″ high without the 2 adjustable shelves (1 1/2″ thick) in place.