Cat Mate Elite Selective Chip and Disc Cat Flap Access with implanted microchip or collar ID Disc(not included ref. 310). Requires 4 AA Batteries 9-12 months use Self lining up to 4 inches, ideal for most types of installation, excludes metal skinned panels. Frame Rain Seal Fully draft and weatherproof brush sealed flap. Cut out Size 6.5"W x 7.5"H Dia 9"