Level 2 Intermediate Dog Puzzle Ball Great For Pets With Little To Nina Ottosson Puzzle Experience; Involves Multiple One-Step Actions.Helps Reduce Dog Anxiety And Redirect Unwanted Behaviors Like Excessive Barking, Chewing, And Digging In A Fun And Exciting Waythree Toys In One With Multiple Ways To Play; Dogs Roll The A-Maze Ball To Remove The Smaller Balls, Then Roll The Treat Ball To Release Treats;Includes A Tennis Ball And A Treat Ball; Compatible With 2.5 In Tennis Balls