Designed to be used with the the QNAP ES2486dc NAS array, the Rail-E03 Rack Slide Rail Kit supports racks measuring about 17.8 x 19.1" in width and height. The rail has a variable depth of between 24 to 36", allowing you to slide the NAS array out for maintenance, configuration, and upgrades. The Rail-E03 is compatible with 9.5 x 9.5mm round-hole and square-hole server racks.