The EVA rainbow ball diameter is 42mm / 1.65in, slightly smaller than a regulation size golf ball, won't fly out of the yard or through the wall, suitable to practice golf in the house or yard. The Foam Golf Ball middle is designed with rainbow stripes, yellow-green white blue, very beautiful and bright, easy to attract cats or kids' attention, and easy to see and find on the yard or lawn. The Golf Practice Balls are made of EVA foam, soft and durable, lightweight and flexible, not easy to break or deform, and won't hurt furniture, glass window, and animals. Rainbow Sponge Balls are perfect for golf beginner golf shots or swing practice, and also colorful balls for cats to chase, carry and hide all over the house.