Tripp Lite's 4POSTRAILKIT1U is an adjustable rackmount shelving system that supports 1U UPS systems as well as other 1U pieces of networking or power protection equipment. 4-post expandable mounting rails offer front to rear support for equipment with 17.5" wide rectangular chassis. Rails adjust to any setting between 20.5 and 36 inches. Includes mounting hardware compatible with square-hole racks. Supports up to 150 lbs.