- THE DOG PUZZLE LEVEL 3! - DIFFICULT LEVEL - REQUIRES YOUR DOG'S REFLECTION AND PERSEVERANCE - DIMENSIONS: DIAMETER 25CM This Level 3 intelligence toy is perfect for dogs who love games where you have to think about getting your reward. It will naturally stimulate her curiosity and require her attention even more. Easy to use for you, hard to solve for your dog! For your part, all you have to do is hide the treats under the sliding boxes so that your dog then takes action, to try to get them back.