It's a fun way to teach eye-tracking, eye-hand coordination and memory simultaneously. All this is accomplished in complete safety as guaranteed by our soft vinyl, air-inflatable, roto-molded construction. The ball has a 7.6cm diameter center core from which six 11,4cm spokes emanate. Each of the spokes has a numbered tip, coordinated to its specific color. Each time the ball is caught in flight the number value of the spoke caught can be added to or subtracted from that player's score.