Chew King Fetch Balls, Extremely Durable Natural Rubber Toys The 2.5" balls fit in the "medium" chuck it head Includes one glow-in-the-dark ball - the fun doesn't end just because the sun goes down Durable, natural, no chemical smell rubber retains shape, bounces well, and stands up to tough chew Safety air vent protects your pup, keeps happy tongues from getting stuck Ditch wet, unsavory tennis balls for a triple-pack of natural rubber fetching fun