Dog' Sudoku Medium Expert - Rainbow In the Rainbow of Dog' SUDOKU(R) Expert , available in size Medium, the movable tiles are made of polypropylene, which has been certified as suitable for contact with edibles. We made this version of the game at request of these pet parents who's dogs produce sizable amounts of saliva, while playing with the puzzles. Please make sure that you pet never plays a game unsupervised since it is an interactive puzzle designed for sharing quality time between the human and his dog. According to dog's behaviorists 15 minutes of mental stimulation with employment of interactive game equivalents to 1 hour of physical exercise. This is especially important for the dogs living in large cities where long walks are difficult and impossible , senior dogs with ailments that do not allow them for prolong outings and those living in cold climates where going outside can put animal's health at risk. How to Play: 1. Hide the treats in the indentations underneath the tiles. 2. Encourage your dog to find the treats by moving the tiles. 3. Praise the dog every time it has moved a tile and found a treat. Only use dry treats that fit into the indentations. Deduct the number of snacks that your dog receives in the game from its total daily ration to keep its overall weight balanced. Tip: We recommend that you start with the Basic or Advanced variation and only move to Dog' SUDOKU(R) Expert when your dog can solve the first two levels without any problems. Allow the dog to watch as you hide the treats in the game to stimulate its curiosity. By being patient, showing it how the game works and giving it encouragement, you can ensure your dog will enjoy playing the game with you and will solve the puzzle. Regularly check the tiles and base for any damage such as splinters and nicks. Clean by wiping with a damp cloth. Do not use abrasive cleaners. Additional information: Dimensions: 12"x12"x2" Weight: 4lb All our games and puzzles are made from certified wood covered with water-based varnish that is not harmful to humans and animals. Please keep the game dry and free of water exposure, as the wooden pieces may swell otherwise. Use only dry treats for playing with our games Keep out of reach of small children since removable parts can be a choking hazard to them.