PetSafe Big Cat Cat Flap Generously sized to give larger cats up to 25 lbs. or small dogs access inside or outside your home Durable plastic frame and hard, transparent flap with pile weather stripping and magetic closure to help keep out weather and drafts Dual, knob-style locks with added strength offer 4-Way access options to control your cat's access in and out of your home: open, locked, in-only (cat can enter but not exit) and out-only (cat can exit but not enter) Slim, sleek styling to match any door design and even install into sliding glass doors and windows For installation in interior or exterior people doors 3/16" to 2" thick; Easy installation with detailed instructions, cutting template and hardware included For Large cats or Small dogs 25 lbs. or less; flap opening size is 7 1/8" W x 7 1/4" H Call, chat or email with our expert US-based customer care specialists six days a week; they are waiting to assist you and your pet with your product needs PetSafe Brand is an industry leading US manufacturer of pet behavior, containment, and lifestyle products since 1991, helping millions of people and pets each year