Rack Cabinets
Rack cabinets have a standard width of either 19″ or 24″. Rack cabinets are used to rack-mount all types of computer gear, recording equipment, video equipment, musical hardware and various electronic devices. They also include computer servers, test instruments, telecommunications components and tape drives. The units are usually bolted to the side frames. If they are unable to do so they can be placed on rack shelves. The height of a rack cabinet is specified in a unit (U) measure or rack unit (RU). 1U (or 1RU) is 1.75″ from top to bottom.