Thick and durable compound prevents dogs being able to pop or chew the ball. Easy to pick up design especially for smaller dogs. Design specific means the dog cannot close its mouth on the ball with enough pressure to pop or chew the ball. Easy to catch and retrieve. The nodules on the surface prevent total blockage of a large dogs airways should the ball get stuck in the throat. 100% safe and non-toxic. Thick and durable this ball that will outlast any tennis ball.