The ball is made out of rubber and is colored yellow, white or black. The ball should weigh 5 to 5.25 ounces (142-149 grams) and be 7.75 to 8 inches (20 to 20.3 centimeters) in circumference. When dropped the ball should bounce 44 to 51 inches (1.1 to 1.3 meters) high.