Horseshoe Puzzle
https://www.youtube.com/watch?v=RmFzByxFg-A
That is a link to how to solve these puzzles, print 2 of the horseshoes and then while the links are half-printed, you can slide the horseshoe and additional links on.. To solve, center the ring and twist the puzzle in half, then just pull it off. Hope you enjoy showing it off two your friends!!