At GoSports, we realize there are athletes of all abilities, so unlike other companies that only provide one style or reaction ball for expert athletes, we developed 3 designs to fit with the age of development of each athlete. The beginner ball is designed to have some bounce variation, but it will not overly frustrate athletes who are just getting started. The intermediate reaction ball is for those who are looking to sharpen their skills as it provides moderate bounce variation. The expert reaction ball is for those at the top of their game who want to be tested to the limits. These balls are a great training aid for a wide variety of sports including baseball, softball, lacrosse, football, basketball and more. Use it solo against a wall, or in a team setting. The unpredictable bouncing will increase your hand eye coordination and prepare you for unpredictable bounces in game situations. The balls are made from TPR rubber and can be used indoors and outdoors.