Nine rack cooking levels for multi-height cooking. The oven interior cooking chamber and racks are made of stainless steel. The grates are mild steel. The oven's exterior is weatherproof and protected by powder-coat stove enamelled paint over mild steel, and the hardware is solid stainless steel. The advanced insulation combines stainless steel and ceramic wool. The insulation keeps all the heat inside the oven. Rest assured, the outside of the oven will not become too hot to touch. The temperature will rise to approximately 60°C over time, ensuring your safety during use.