If your cat is not, or cannot, be microchipped, the SureFlap RFID CollarTag is a small, lightweight alternative that can be attached directly toyour cat’s collar and used with the SureFlap RFID Microchip Cat Flap. Likemicrochips, each collar tag has a unique code, to prevent any non-residentpets or strays from entering your home including other pets in theneighbourhood with a SureFlap collar tag, or any other type of collar tagused in selective pet doors. *The collar tag is not compatible withSureFlap Microchip Cat Doors with a serial number of 1152201 or lower. Forfurther information regarding suitability for your cat please download theinstruction manual here: DualScan Manual.If your cat is not, or cannot, be microchipped, the SureFlap RFID CollarTag is a small, lightweight alternative that can be attached directly toyour cat’s collar and used with the SureFlap RFID Microchip Cat Flap. Likemicrochips, each collar tag has a unique code, to prevent any non-residentpets or strays from entering your home including other pets in theneighbourhood with a SureFlap collar tag, or any other type of collar tagused in selective pet doors. *The collar tag is not compatible withSureFlap Microchip Cat Doors with a serial number of 1152201 or lower. Forfurther information regarding suitability for your cat please download theinstruction manual here: DualScan Manual.