Tripp Lite's SR18UB premium Smart Rack 18U 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 SR18UB is compatible with Tripp Lite's extensive range of rackmount accessories, enabling you to customize your solution to meet any requirement. The SR18UB is compatible with all standard 19-inch rack equipment & features front & rear pairs of vertical rails with square mounting holes. The rails are adjustable in quarter-inch increments to accommodate equipment depths from 3 to 32.5 inches, ideal for standard server installation.