HP 918321-051 is a black French-layout keyboard for the Pro x2 family, intended to provide the keyboard input surface for a compatible tablet setup. Its French regional variant makes it suitable where that layout is needed, while the black finish matches the listed part description.
HP’s service guide identifies the 918321-xxx keyboard as a spare part for the HP Pro x2 612 G2 and maps suffix -051 to France. This replacement part is therefore specifically identified as the French variant in that keyboard series, rather than a different regional suffix.