HP 864104-101 motherboard shielding is a shielding part for AMD-based systems. It is intended for use with the motherboard and is listed as compatible with the HP 20-C028 All-in-one PC.
This part is a system-specific replacement component for that listed configuration. The confirmed reference is 864104-101; the listing describes it as motherboard shielding for AMD systems. It is not a motherboard or a complete computer, but a shielding component intended to accompany the board.