Highquality steel automatic nonmanual design can adjust the tension adjustable screw to close slowly or quickly choose the return closing speed suitable for the environment where the is placed. this is to reduce the strength when closing the door to protect the door from damage and reduce noise. feature The automatic is made of steel and zinc alloy using onepiece molding process and multiple assembly processes to make the whole product durable. Please measure the door before placing an order it is suitable for a door weight of 2040kg. The closing strength of our s can be adjusted according to your personal needs using the adjusting rod tight or tight. This kind of is not suitable for heavy doors and large doors.