These extra doors for the Nina Ottosson Dog Brick are for replacing damaged or lost doors from the game. Each pack comes with five doors to keep your pup puzzling and practicing their nosework! Easily snap doors on the hinges of the red boxes to cover the treat compartments and watch your pup puzzle it out! Puzzle games are great for mental stimulation and dog enrichment by testing your dog's problem-solving skills. Remember: No toy parts are indestructible. Do not leave parts with unsupervised pets. Remove and replace if damaged. PLAY BY THE RULES – SAFETY & CARE: When choosing a toy, make sure to choose an appropriate size/style/level for your dog. No toy or game is indestructible. ALWAYS supervise your dog closely, teach your dog how the game/toy works. Do not leave the dog alone with a treat game/toy, do not let the dog chew on the game/toy or pieces. Inspect regularly for damage and remove if broken, or if parts become separated, as serious injury may result. For dogs only, not a children's toy. When empty, store until next supervised use.