One of the best ways to bond with your dog while giving the pet plenty of exercise is by playing fetch with tennis balls. And one of the more unique tennis ball collections you'll find is the Zanies Puppy Pride Tennis Balls for Dogs. This six-pack of rainbow colored tennis balls features balls of orange, red, yellow, green, blue and purple. The 2.5-inch diameter tennis balls offer a bit of flexibility that allow smaller dogs to grip the balls in their jaws. Play time with your dog will be great with this collection of tennis balls!