Baboni pet door is composed of metal steel and aerospace: grade aluminum alloy. Elaborately built in combination with automotive laser welding technology. Both practicality and home decoration beauty. The soft and flexible double flap features a strong magnetic closure, which can effectively save energy. The attached slide: in metal panel helps protect against extreme weather. And provide security for your home when the door is not in use. The telescoping tunnel accommodates walls that are 4 3/4 : 7 1/4 in thick.