The term "stainless steel door sills" refers to a type of trim or molding that is made from stainless steel and used to cover the gap between the doors and the frame. These are often found in cars, trucks, and other vehicles as well as in some residential settings. The purpose of these metal pieces is both functional and decorative - they help prevent water and dirt from getting into the doorframe while also adding a touch of elegance to the overall appearance of the vehicle or room.