ThermoPlastic pet door features inner telescoping frame that adapts to doors of 1-1/4 In. to 2 In. thickness. Includes impact resistant super-strong thermoplastic， clear vinyl flap with patented edges won't warp from use or extreme temperatures， and floating bottom threshold for perfect seal. Lock-out slide keeps pet out of mischief when unsupervised. Features tamper-proof mounting so the door cannot be removed from outside. Easy installation - average installation time is 20 minutes. How to select the right pet door: Step 1: Measure your pet from the top of the shoulders to the chest， just behind the front legs. Step 2: Determine your pet's weight. Step 3: Select the correct door size based on your pet's measurements and weight. Opening Size: 10-1/2 In. x 15 In. \nPet Size: 36 to 90 Lb. \nMaterial: Thermoplastic \nColor: White \nLockable: Yes \nThickness: 1-1/4 In. to 2 In. \nCut Out Dimensions: 11-3/4 In. x 17-3/8 In. \n

X-Large (10.5"W x 15"H)