Brightly colored Gymnic Classic therapy balls for stretching or balance therapy. Made of heavy-duty molded vinyl, four times thicker than beach balls. Support up to 440 lb. The Classic Plus balls are burst resistant therapy balls specifically designed for high-risk patients or high performance workouts. Even when purposely damaged with knives or scissors, there is no danger of big splits or sudden loss of pressure. Latex free. See the chart below for the correct ball size.