KONG Sport Balls are better than a tennis ball. Made with extra-thick rubber walls, these toys are tough enough for serious games of fetch. Give them a throw and watch your dog go crazy for these rugged, bouncy balls.
 
X Small - 3.8cm (comes in an assortment of 3 balls)
Small - 5cm (comes in an assortment of 3 balls)
Medium - 6.3cm (comes in an assortment of 3 balls)
Large - 8.2cm (comes in an assortment of 2 balls)