For the design of drying heat sensitive and easy decomposition, easy oxidation material, inert gas into. Characteristics: 4-sides heating method, temperature conduction by shelves, more efficiency. With inflatable port, once-forming thermostability silica gel sealant strip, with good tightness. Double observation glass window, inner is explosion – proof glass, outside is resin protection plate, more safety. Fastening handle, convenient for opening and closing.