This SmartRack open-frame rack has no doors or side panels. It features integrated baying tabs to combine multiple racks in rows for data center applications. It is compatible with hot-aisle / cold-aisle configurations. The SR42UBEXPND houses 3500 lb (1588 kg) of standard 19" rack equipment in 42U. Square mounting holes on its rear and front vertical mounting rails adjust in quarter-inches increments from 4 to 37". Each rack space is numbered for at-a-glance reference. An easy-to-read depth index ensures consistent rail placement without requiring time-consuming measurements. Two vertical mounting rails support toolless button-mount 0U installation of four compatible PDUs and cable managers. This makes it easier to route cabling to rack equipment and reduces cord clutter. Components are grounded to the enclosure frame. Threaded grounding points are provided for connection to the facility earth ground. To simplify deployment, the SR42UBEXPND includes preinstalled casters that enable it to be easily maneuvered into the desired location, where it can be secured by adjusting the preinstalled levelers. Note: the casters are intended for minor position adjustments and are not designed for moving the enclosure over long distances.