Constructed of stainless steel to with stand high-volume use. Its door exterior stays cool to the touch to prevent burns. This unit uses convection and microwave technology to thoroughly heat product. A catalytic converter is built in to prevent the need for a vent. Internal components can be accessed from the side, while the air filter is accessible from the front. this unit has a 15-minute preheat time and maximum cook time of 60 minutes. the Merrychef E3 high-speed countertop convection oven has a USB port for updating recipes or transferring data.