PETSAFE ALUMINUM WALL DOOR SM Telescoping tunnel allows for installation into walls Fits walls 4 3/4" to 7-1/4" thick Dimensions - 9-3/4" x 13-1/2" Flap Opening Dimensions - 5" x 7" PETSAFE ALUMINUM WALL DOOR MED Imagine a pet door installed behind a couch or in a utility room. Our Wall Entry Door can be installed in a number of exterior wall materials, including siding, stucco and even brick. Double-flap system insulates for energy efficiency Easy do-it-yourself installation kit Aluminum frame with durable plastic tunnel extension Telescoping tunnel allows for installation into walls Extension kit sold separately to extend beyond 7 1/4" (18 cm) Fits walls 4 3/4" to 7 1/4" (12 cm - 18 cm) thick Dimensions - 12 3/4" x 17 1/2" (32.4 cm x 44.5 cm) PETSAFE ALUMINUM WALL DOOR LG Telescoping tunnel allows for installation into walls Fits walls 4 3/4" to 7-1/4" thick Dimensions - 14 3/4" x 21-1/2" Flap Opening Dimensions - 10" x 15" PETSAFE ALUMINUM PET DOOR XLG Dimensions - 16 3/8" x 27 1/4" Flap Opening Dimensions - 13 5/8" x 23" Fits doors from 3/8" to 2" thick Great for pets up to 220lbs PETSAFE ALUMINUM PET DOOR SM 6 pk PETSAFE ALUMINUM PET DOOR MED Dimensions - 12 3/4" x 17 1/2" Flap Opening Dimensions - 8 1/8" x 11 3/4" Fits doors from 3/8" to 2" thick Great for pets up to 40lbs PETSAFE ALUMINUM PET DOOR LG Dimensions - 14 3/4" x 21 1/2" Flap Opening Dimensions - 10 1/8" x 15 3/4" Fits doors from 3/8" to 2" thick Great for pets up to 100lbs