This innovative ball can be used as a horse toy for hours of enjoyment, as an aid in desensitizing horses, or as an exercising tool to help rider improve balance and seat position. Perfect for average-sized horses and riders. Includes 10-minute Stacy Westfall DVD teaching proper uses for the ball. Use caution around sharp objects. Supervision recommended at all times. Pump and tape measure included. Medium/Blue - 30" height and 93" circumference when inflated or Large/Red - 39" height and 124" circumference when inflated.