The e-Cat Electronic Pet Door Extra Collars allow pet to activate the Ideal e-Cat Electronic Cat Doog. Includes one e-sensor "breakaway" collar Great for people with multiple cats.
The Magnetic E-Sensor Collar is meant for use with the Ideal e-Cat Electronic Pet Door (not included). The sensor on the collar keeps other animals from entering while allowing your pet to use the door. 9-Volt battery not included.