Champion Sports - CSIRXTHRMSET Rhino Skin Thermo Grip Dodgeballs change color beneath your hand. They are thermo-enhanced to cause the heat-activated color change. High-tech design provide a long-lasting, no-sting product that's perfect for gym class, the playground and more. They are made for indoor and outdoor use. Bright colors, a lightweight foam core, soft exterior and tear-resistant coating make these balls a top choice for dodgeball, foursquare and other popular playground games. These balls are sting-resistant, low-density and low-bounce. Set of balls comes with a mesh bag for easy transport.