Cat Mate Electromagnetic Cat Door helps ensure that stray pets will not enter your house. Your pet simply wears a magnet attached to its collar which is identified by a sensitive, fast reacting electromagnetic circuit suitable for pets of all temperament.This neatly designed door is suitable for toy breed dogs and cats.Overall size: 7 5/8″ x 9 1/2″. Cut out size: 6 5/8″ x 8 5/8″. Flap size: 6″ x 5.75″.