Into the door is a metal door or special door
Into the door does not belong to the special door, but not all of the door into the door are metal doors.
General residential door into the door is the metal door, the most common is the anti-theft door, according to energy requirements will have insulation performance, according to fire requirements will have fire performance.
Special doors and special doors compared with the special purpose of the door, including radiation doors, air defense doors, noise doors, smoke doors, dust doors, anti-tornado, anti-shock doors,
