Cat Mate Electromagnetic Large Cat or Small Dog Door - White Suitable for the largest of cats or small dogs (yorkshire terriers, pekinese, dachshund etc). Self lining to 60mm (2.375) thick. Includes 1 x Cat Mate Cat Collar Magnet (Ref. 257) and 1 x Dog Mate Dog Collar Magnet (Ref. 258) Battery powered. 1 x PP3 9V battery (not supplied) gives approximately 12 months operation 3 year guarantee.