Universal spring door closer universal fit for commercial doors, escape doors, security doors, fire doors and so on. Made of an environmental aluminium alloy casting body, with a built-in anti-external force device offers protection for the door, door frame and door closer, ensuring durability in use. Two independent valves to control the closing speed and the latching speed, self-regulate the mechanism to meet your needs. Will slow down after the door is opened to 60 degrees, preventing the door lock and door product damage or wall collision caused by the door opening speed being too fast. Over 500,000 times open and close testing, at least 96 hours salt spray corrosion test, 100% inspection.