Tripp Lite's SR25UB premium Smart Rack Enclosure Cabinet is packed with features designed to simplify rack equipment installations & rack equipment maintenance: top & bottom cable routing ports, perforated door & side panels to promote efficient airflow, adjustable vertical mounting rails & more. & as part of the Smart Rack family, the SR25UB is compatible with Tripp Lite's extensive range of rackmount accessories, enabling you to customize your solution to meet any requirement. The SR25UB ships fully assembled for quick installation. The SR25UB has 25U of capacity & is compatible with all standard 19-inch rack equipment. The front & rear pairs of vertical rails feature square mounting holes & are numbered by rack space for easy reference. The rails are adjustable in quarter-inch increments to accommodate equipment depths from 4 to 37 inches.