They’ve got to bring those back!!!! I spent almost the entire early 80s playing that game.
If you’ve never heard of ’em, they were hard plastic rings, about the diameter of a dime, that came loose in a pack. The rings were split so that you could put the individual colored rings around a center ring. You fretted over the color of the rings in the pack you were selecting and you alternated the colored rings as you put them together to make pretty and unique combos.
You would buy more packs to make the jacks denser. Not too dense though! They had to have enough floppiness as to not pop off of your hand and accidentally hit the ground while you were furiously tossing and catching them.
If I remember correctly, you ended up with 5 jacks that almost looked sorta like today