Worth the extra dough to get this rubber ball because the cheaper balls are made of PVC (Plastic fused with chlorine). PVC is toxic to manufacture and is the last thing you want ending up in our landfills. This ball is very strong. I've had it for about five months and I use it mainly to stretch my back, but it comes with a chart that has many exercises you could do to strengthen your core. I absolutely love this thing!
Rating: [5 of 5 Stars!]