This is a headphone stand or hook for use on desks with gaps in between the tabletop and the bottom. The stand is just wide enough to prevent it from rolling and dropping the headphones.  Reinforcement structures will prevent the hook from dipping and dropping the headphones. Use this design if you like minimalism and aren't happy with the thick stands that you see on the site. 

After using it for a while, I've seen that the design will not work well with PLA filaments. You'd need to use something stronger.