The HPE ProLiant DL380 Gen11 NS204i-u Internal Cable Kit (P52152-B21) is a cable kit for configuring the NS204i-u boot option in a DL380 Gen11 server. It provides the internal cabling required for that device configuration.
HPE lists this kit as required when the NS204i-u Gen11 Hot Plug Boot Option Device is selected. The QuickSpecs set a maximum quantity of one for the kit. This is a specific internal cable kit for the DL380 Gen11 NS204i-u arrangement; the listing does not identify it as the boot device itself.