This cantilever rack shelf is a universal equipment rack suitable for 19-inch cabinets and racks . It can be used to place electronic and music equipment and is suitable for computer rooms, recording studios, studios, stages, and small home network installations. The rack shelf is perforated with a ventilation design , which can dissipate heat, promote safety and air circulation, and keep the usage space cool. The ventilation design can also extend the service life of your equipment. Accessories of Each Shelf: 1 Pc of 12" deep shelf tray 2 Pcs of 1U holding brackets 1 Wrench 4 x M6 Rack screws 4 x M6 Cage nuts 4 x M5 Screws and nuts