The ThinkServer Tower to Rack Shelf Conversion Kit lets you quickly install the ThinkServer into a rack enclosure.Fits most 19-inch four-post ""EIA Standard"" cabinet style racks with either square or round mounting holes Tool-less telescoping slide rails snap in quickly and easily into the rack Shelf easily attaches to slide rails. Shelf design lets you slide the system into and to full extension out of the rack for ease of service and provides a nested recess for the system eliminating any unwanted movement. No special bezels required Allows technicians to install the ThinkServer securely on the shelf/rail system will support for weight of system at full out position for ease of service The kit also includes a Cable Management Arm (CMA), for managing cables.