Tripp Lite"s 4POSTRAILKIT1U is an adjustable rack mount 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-Inch 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.