SureFlap Microchip Pet Door Works with your pet's existing microchip to keep intruder animals out Compatible with all microchip formats worldwide Also works with the SureFlap RFID collar tag (one tag supplied with the product) Curfew Mode - program the door to lock and unlock at specified times Requires 4 C cell batteries which last up to a year with normal use (not included) The exterior dimensions of the pet door are 10.315 inches (w) x 11.063 inches (h) and the cut out dimensions for mounting into a door/wall are 8.14961 inches (w) x 9.2126 inches (h)