The Sure Flap Microchip Cat Flap uses your cats existing microchip like an electronic door key to keep unwanted animals out of your home. The unique number on your cats microchip is permanently stored in the memory of the cat flap, even when the batteries are removed. When your cat approaches the cat flap from the outside, it reads their microchip and the door unlocks. It remains locked for any other animals who try to gain entry, creating a secure environment for your cat. Resident cats are less stressed once they realise their home is no longer being invaded. Key features Makes cats feel more comfortable in their own homes No more fights or spray marking in the house Compatible with all common microchips and the Sure Petcare RFID collar tag (not included) Battery powered requires 4 x AA batteries which last up to a year (not included) Low battery indicator light gives you plenty of notice when the batteries need changing Can be installed in doors, glass or walls Four-way manual lock allows greater control of your cats entry or exit Stores up to 32 pet identities When installing into glass, the Sure Flap Mounting Adapter is required. This is because glass requires a circular hole. The mounting adapter ensures that the flap fits into the glass correctly with no gaps. The adapter can also be used when installing into a wall as it leaves a smooth and clean finish.