Frisky felines crave their freedom and now they can have it safely and securely with the Ideal e-Cat Storm Door Cat Door. Designed for use with the E-Sensor collar which controls the door this door opens and closes automatically just for your cat. It"s made of with a sturdy aluminum telescoping frame and the transparent flap has four-way operation. The weatherproof design allows you to mount the door indoors or outdoors. It"s the perfect way to give your cat her independence and ensure that no other critters come into your home. Additional E-Sensor collars can be purchased separately. Overall dimensions - 9.125W x 4.125D x 14.5H inches. Flap dimensions - 7W x 9H inches. Hole dimensions - 8.25W x 13.5H inches. Suggested pet weight - up to 25 pounds