This is a Chicken Head Knob, or Pointer Knob. These little guys will fit right on your lcd display of your printer. As a guitar player, I love the look of vintage tube amps, so I wanted to bring an aspect of that into 3d printing. 

I printed mine in black, which is most common. There is a version with and without an indent/marker, which you could paint white. FDM printers may have trouble printing the marker because of the level of detailed required to do so.