The PDU4PKIT Rear Support Rail Kit adds rear mounting support for select Tripp Lite 1U ATS PDUs in EIA-standard 4-post racks and rack enclosures. With sliding support rails attached to both the rack and the PDU, the PDU4PKIT allows the PDU to support heavy plugs and power cables hanging from its rear panel without sagging under their weight. Front rail segments attach to compatible PDUs with included mounting screws. Rear rail segments attach to rackÃ‚â€™s vertical mounting rails with user-supplied cage nuts and mounting screws. The adjustable sliding rails are compatible with rack depth settings from 22.8 to 36 inches. The convenient rails also help one person mount the PDU without assistance from others. Works with Tripp Lite PDUMNH16HVAT, PDUMNH20HVAT, PDUMNH30HVAT, PDUMNH32HVAT and other PDU models that specify compatibility.