The 4POSTRAILKITWM wall-mount rack shelf kit provides extra support for heavy UPS systems, PDUs or other rack-mount components that weigh 150 pounds or less. It includes two adjustable mounting rails that attach to the mounting rails of your EIA-standard 19-inch wall-mount enclosure. Constructed using cold-rolled steel with a durable powder-coated finish, this heavy-duty rack rail kit comes with mounting hardware compatible with square-hole racks. The rails offer front-to-rear support for equipment with 17.5-inch-wide rectangular chassis. They also adjust to any setting between 14.5 and 23.5 inches and leave the rack’s front and rear mounting holes free to attach equipment. Setup is hassle-free and saves money and time on installation. Threaded-hole rack installation is also supported with user-supplied mounting hardware.