Each set contains 4 orange cylinders for blocking 4 drawers and 4 regular size cylinders where treats are placed. After removing cylinders the dog can spin the circular part of the game to reveal more treats hidden inside. Happy Birthday! This is a special occasion puzzle that will be a great addition to the celebration of the birthday of your dog. By placing the sticker with number (1 to 18) provided with the package you can make this special day even more special by giving your loved one intelligent game that will exercise his mental and physical abilities and allow to spend quality time together. By adding and removing tokens you can adjust level of difficulty of these puzzles to age and experience of your dog.