Freight lift doors may vary depending on the type of freight lift used. Doors on freight elevators are generally made of strong and durable materials, such as steel or aluminum. Several types of goods elevator doors that are commonly used include sliding doors, folding doors, and harmonic doors. These doors are usually equipped with locks and automatic locking systems for the safety and convenience of elevator users. Apart from that, there is also a sensor on the goods lift door which functions to prevent objects or people from being pinched when the door is closed and the elevator is operating.