The Dog Rumble Puzzle interactive dog ball puzzle toy from Nina Ottosson by Outward Hound is two toys in one! It includes a treat ball and maze ball for extra enrichment and extended play, keeping your dog busy and mentally stimulated. This interactive dog ball provides both physical and mental exercise, making it a fun way for your dog to practice its problem-solving skills. The Dog Rumble Puzzle can also be used with a standard 2.5″ tennis ball or Outward Hound’s medium-sized Squeaker Ballz tennis balls. This Level 1 puzzle is fun for all dogs regardless of age, size, or breed.