HPE 792837-001 is a long power cable for connecting a PCI component to a controller inside compatible equipment. It provides a direct power connection between those components.
The cable is 400 mm (15.7 inches) long, providing a fixed length for routing between the connection points. Both ends use straight female 3-pin connectors, matching the connector arrangement identified for this part.
This is a specific internal power cable, rather than a general-purpose mains lead.