Boltless design: The boltless design makes it easy to built and disassemble the rack, no bolt and no nut required, a rubber mallet recommended for assembly (rubber mallet not included, we give a pair of gloves for your convenience). Adjustable height: Featuring the height-adjustable design, this storage shelving unit can be built as you need, vertically or horizontally. Or, you can remove the board to get bigger space for large items.