This electric wall heater has two heating elements. The device has a switch that toggles between "half" and "full" ie one element connected or both. There are thin metal plates that sit perpendicular to both, with the elements going through them. These are to increase the surface area. The idea is that when the air touches the hot metal, there is transfer of thermal energy by conduction. The more metal that is touching the air, the more of this can happen at once and the faster the air heats up. The air expands, becomes less dense and rises. This allows colder air from below to move in to touch the plates.
