Narrow depth makes this set work where a standard rack will not. At 12 inches deep and 30 inches wide, each of the four units hugs a wall, fits behind a car door swing and still carries 440 lbs per shelf, 2200 lbs in total. Every board is MDF over a metal frame, so screws and washers stay put instead of dropping through mesh. Rolled edges soften the shelf lips and eight non-slip pads protect a sealed floor. Shelf height moves in 1.5-inch increments, and the frame splits into two horizontal workbenches when a warehouse or basement corner needs a work surface instead of a tower. A mallet, gloves and instructions come with each 21 lb unit, so no power tools are needed to build the run.