15 in. x 10.5 in. Extra Large Deluxe Aluminum Frame Pet Door Inner telescoping frame adapts to all hollow core and solid doors of 1/2 to 1 3/4 thickness. No need to build an inner frame. High quality aluminum construction (White). Clear flap allows your pet to see if the slide is in place. Tamper Proof Mounting System, door can\'t be removed from outside. Thermo-Insulated Lockout Slide