Originally Posted by plankton

that's a scaled down disc golf target (basket) that utilizes bottle caps as the projectiles instead of full sized discs. It works fundamentally the same as the full sized version where you throw the projectile (a bottle cap in this case) at the center of the chains and the projectile hits the chains and falls into and comes to rest in the basket.

For more info on the actual sport:
https://www.pdga.com/introduction