You've seen the problem.. smaller students battle with ankle rings that fall off their heel before they even start; while older students often have to take off their tennis shoe just to get the ankle ring in place.. both problems are frustrating and take away from the fun of using "ankle jumpers". Problems solved! The Ball Hop II has an open-and-close "handcuff" ring that won't slip off small shoes sizes, and avoids the need to take larger shoes off. Just press down on the release tab to open the ring, and it "click-lock" it closed. The new design now includes fill-able, speed control FLow Pucks that improve rotation, and they're removable from the rope for floor hockey play in essence giving you 6 free pucks. Sold in sets of 6 (1 of each color).