An diagonal wall-mounted range hood isn't right above your cooktop, but is mounted at an incline. This means you'll have more space, so you won't bump your head as quickly while you're cooking. This type is also known as head-free or diagonal. These diagonal range hoods have a striking appearance, which means they don't look like standard range hoods. Most models have a width of 90 centimeters and are suitable for large or open kitchens.