PetSafe One Piece Pet Door Classic Replacement Flap - 8" x 11" - Medium - 4-0111-11 Size: Medium Measures: 8" x 11" Soft, smoked vinyl, single flap for energy efficiency Replacement Pet Door Flap for the Classic Pet Door and the Deluxe Patio Panel Door and Wall Entry Pet Doors Medium Replacement Flap (8" x 11") - Fits the Classic Frame 10 3/4" x 14 3/4", Deluxe Patio Frame - 11 1/2" and Wall Entry Frame - 12 1/4" x 17 1/8"