These 19 Inch to 23 Inch Rack Adapters are used when 19 Inch Rack or Cabinet mounted devices are mounted on a 23 Inch wide system. Devices commonly requiring these Adapters are: Patch Panels, Hubs/Routers, Feedthru Panels, and A/V components. These adapters are made from premium 14 gauge steel finish, 10-32 Pemnuts inserted in the inside edge for mounting in a satin black industrial coating. Each pair of adapters is boxed and includes mounting hardware.