This is a vertical display stand meant for the Lego Technic Batmobile set, you can see in the second picture where to fit the notch at the top, and what it looks like on my display shelf. 

Other models on the shelf:

Batman bust - https://www.printables.com/model/554147-the-batman

Minifigure display stand - https://www.printables.com/model/706359-minifigures-display-stand-lego-compatible