Inner telescoping frame that adapts to doors of 1 1/14-inch to 2-inch thickness
Tamper proof mounting system, pet door cannot be removed from outside.

Impact-resisting super-strong thermoplastic clear flap allows pet to see if slide is in place. Simple 4-step installation, average install time: 20 minutes

Flap size: 5-inch by 7-inch. For cats up to 12 pounds