Bracket Enhances Functionality of Enclosures and Open Frame Racks: The SRPDU4PHDBRKT allows the addition of up to three vertical PDUs or cable managers to a Tripp Lite rack enclosure or open frame rack, helping you avoid the need to invest in a larger rack configuration. Upper and lower brackets attach to the frame of a standard or heavy-duty rack enclosure using the included screws and cage nuts. Included adapter plates allow connection to mounting rails in 2-post or 4-post open frame racks. Supports Toolless Mounting of Up to 3 Vertical PDUs or Cable Managers: Up to three vertical PDUs or cable management accessories can be mounted to the SRPDU4PHDBRKT brackets. Keyhole slots support toolless button mounting. The brackets also have equipment mounting holes for attaching PDUs and cable managers with fasteners.