This is a clip-on cable guide for the gaming headset Beyerdynamic MMX150. It removes scratching noises induced by the cable by guiding it away from the body. 

The clip is held in place by a snug fit on the metal piece (probably wont work with very small heads). The cable is pushed into the groove on the backside.  

I printed it with a Prusa MINI with "0.15mm QUALITY" profile out-of-the-box. No supports needed.