A:Answer Hey there! We are happy to help. The recommended cutout depth when installing this model in a cabinet or wall cutout is 20" (50.8 cm). The installation hardware comes with an exhaust duct, but keep in mind that If building over a wall oven, be sure the clearance between the wall oven and the microwave oven is a minimum of 3 inches. If additional assistance is needed, please connect with us directly via Live Chat from our website, Monday through Friday, between 8:30 am and 8 pm EST. ~Keyanna