I'm asking about the heating coils in it. I understand the conduction heater in bowl has no contact. I'm asking about the coils that heat up the air for the convection portion. What material is the heating coils made of for that portion. I think Volcano uses aluminum, V3 Pro uses Kanthal. What does Airvape Legacy Pro use?There is no contact with the coil. It is a gold plate zink-alloy oven where the heat meets the herb.