This shelf will fit all standard 19" EIA upright relay racks or cabinets. Both 10-32 and 12-24 mounting screw kits are included allowing mount on either thread pattern. The shelf occupies 2 Rack Spaces. The shelves are made from premium 16 gauge steel finished in a satin black industrial coating. Applications include shelf mounting heat sensitive hardware such as: * Hubs and Routers * Ham Radio Gear * Audio and Video Equipment * Laser Printers