Made of durable rubber with an interior spun bladder.
Number 6 ball.
9" diameter - 28.5"-29" circumference.
To measure the size of your current ball: Inflate the basketball to the recommended air pressure. Place a piece of string around the circumference of the ball and mark the length of the circumference on the string. Remove the string from the ball and lay the string on a flat surface, in a straight line. Measure the length of the string that you have just marked to obtain the circumference of the ball. Divide the circumference of the ball by 3.14 to give you the diameter of the ball.