Replacement key for the microchip cat flap. Compatible with the microchip cat flap. Key rings for easy attachment to your pet's collar are included. No batteries required. Transparent key with a copper ring inside. Program your microchip cat flap with up to 20 keys. Approximately the size of a bottle cap. PetSafe has created a real eye-catcher with the new key fob for your cat. This small tag is suitable for any cat and allows you to have complete control over which animals have access to your home and which do not. The tag, which works as an RFID sensor, uses state-of-the-art technology to ensure that only your cat can pass through the door while unwanted guests stay outside. Programming the key fob is easy and quick and can be done by you. The best part about the PetSafe key fob is that your cat will always carry it with them and it requires no batteries. Simply attach it to the collar and your cat can come and go as they please. The tag is so light and unobtrusive that your cat won't even notice it's there. The PetSafe key fob is not only a great addition to the PetSafe cat flap, but it is also suitable for the PetSafe dog fence or other electronically secured PetSafe facilities. Discover the benefits of safety and comfort for your cat with the brand new PetSafe key fob. Order today and give your cat the freedom they deserve.