Our stacking shelves in a set of 3 x 3. Additional units can be added to this set if desired. These are sold flat packed and require assembly and an alan key is provided. W122 x D28.5 x H121cm Inner dimensions: W37.5 x D28.5 x H37.5cm Add‐on shelving units can only be attached to the side panels of a set unit. Please note, a shelving set unit cannot be expanded upwards when placed vertically and cannot be expanded sideways when placed horizontally.