It acts like a spring door and can ensure that the door is opened accurately and timely. Close to the initial position. I recommend you to refer to the RDC-04 concealed fireproof door closer of Lelang Hardware. The door closer is made of high-quality die-cast aluminum alloy body and protected by three layers of bright paint to prevent oxidation and discoloration. High-carbon steel gear shafts and racks are subjected to high-frequency quenching and tempering treatment, with small deformation and flexible operation.