ChickenGuard Self-Locking Chicken Coop Door Kit; Help prevent sly foxes and other crafty predators from raising the coop door and accessing your feathered friends with the ChickenGuard Self-Locking Chicken Coop Door Kit. The innovative self-locking mechanism means that once the strong aluminum door is fully lowered, the wings are automatically released to lock it securely in place. Give your hens something to cluck about with this smart upgrade to their home sweet home.