The enameled surface has microscopic pores, and when used for a long time, it will rust, which is very bad for human health. This will not happen if you use a 304 food grade stainless steel liner. Senge's steam oven uses a one-piece stretched seamless steam baking liner, smooth and seamless inside, high temperature and corrosion resistant, easy to clean, longer service life, but also no safety hazards.