Exercise & Fitness: Powerball Neon White Pro Signature Exercise Ball Perfect for golfers, musicians, squash, tennis, fencing, basketball, badminton, archery, cricket etc. Neon White Powerball comes with a digital speedmeter/counter. Limited edition gyroscope has a top speed in excess of 16,000rpm. Just the size of a tennis ball and weighs under 300grams. Not for children. Ages 18 years and up.