When I first started using Plickers for students assessment I printed off the cards on full sheets of paper, then I saw on Twitter other PE professionals had created Plickers magnets or Plagnets. This idea was a complete game changer, after using versions created by others I finally realized what I liked and didn't like about different versions so I created my own. They have worked out great and grades K-5 utilize them on a daily basis for self assessment on success rate, skill knowledge, and sports history.
I have shared my version of my Plickers magnets here, please feel free to use them!
Plickers Magnets.pdf