PetSafe Wall Entry Pet Door with Telescoping Tunnel, Pet Door for Dogs and Cats, Available in Small, Medium and Large DURABLE, ALUMINUM FRAME: Durable plastic telescoping tunnel fits wall thickness 4.75 in. - 7.25 in. The Frame dimensions are 12 1/4 x 17 1/8 inches,the classic cut out size is 9 9/16 x 14 5/16 inches and the new freedom cut out size is 9 7/8 x 14 3/4 inches DOUBLE-FLAP DESIGN: The door has two replaceable flaps that help keep out weather and provide energy efficiency CONTROLLED ACCESS: The slide-in closing panel is provided for added insulation and control of your pet's access EASY, DO-IT-YOURSELF INSTALLATION: Installs into several wall types including all types of siding, stucco and brick; cut-out template and step-by-step instructions included PET SIZE: Recommended for pets up to 40 lb.; pet door flap opening measures 8.25 in. W x 11.25 in. H PRODUCT SUPPORT: PetSafe brand's U.S.-based Customer Care experts will be glad to help; call Monday through Saturday at 1-800-845-3274 EXPERIENCE: PetSafe brand has been an industry leading U.S. manufacturer of pet behavior, containment and lifestyle products since 1991, helping millions of people and pets each year