Often a 42U enclosure—which is the most common—is not required. Smaller options such as 25U, 30U or 36U will provide more than enough rack mounting space for servers, UPSs, rack PDUs, switches and other equipment. The smaller options enable you to use the space on top for monitors or other equipment. Features such as perforated doors, adjustable rails, locks and casters are still available in these sizes. Wall mount enclosures can also be considered when a full-height rack or enclosure isn’t necessary.