Hook for hanging headphones diagonally on the corner of the desk.

This design fits on the corner of an IKEA Linnmon table top (34mm).
You also need one small IKEA Fixa pad for a better grip.

FIXA pads: https://www.ikea.com/gb/en/p/fixa-stick-on-floor-protectors-set-of-20-grey-00431151/