(Ani Mate) The Cat Mate Elite uses the latest in RFID technology and offers major advancements in pet access control. Entry and exit is operated by either the ID microchip your veterinarian implants in the cat’s neck, or our unique electronic collar ID discs (not included) for up to 16 cats. Keeps all other animals out. The cat flap has a secure, 4-way locking system. Takes 4 AA batteries (6 to 9 months,) not included. Self-lining to 2”. Suitable for single/double glazing, doors and panels, including metal. Wall Liner available for wall installation (not included).