Not tall. According to the inquiry of Panasonic Hi-Poly Tray official website, the idle rate is not high, and Panasonic Hi-Poly Tray is made of ceramic materials as a whole, which is a safe ceramic electric furnace. Ceramic electric furnace is a kind of stove which uses the thermal effect of current to convert electric energy into heat energy. Its main structure consists of a heating plate, a microcrystalline plate, an electric control system, a temperature control system and a furnace body. The heating plate of ceramic electric furnace consists of iron-chromium heating plate and insulating plate.