Lockable cat door features inner telescoping frame that adapts to doors of 1-1/4 In. to 1-3/4 In. thickness. Includes and unbreakable Lexan flap and 4-way locks. Set the lock to give free access in or out in but not out out but not back in or completely locked in both directions. Clear flap allows pet to see if slide is in place. Ideal for cats up to 12 pounds. Installation measurements: 7-1/2 In. x 7-1/4 In.