Keep the door open. 90°~180° - When your opening angle is greater than 90°, this door closer can hold the door open at any angle. You don't need to use force or a door stop to keep the door open. If you like a well-ventilated room or frequently need to move goods, this will be your best choice. All you have to do is open the door. Less than 90° and it will automatically shut off. High quality; Adjustable speed - Hydraulic door closer made of high-quality aluminum alloy. It closes your door automatically and quietly. Improve your quality of life. You no longer need to shout "close the door!" The door closer has 2 valves that independently control the closing and locking speeds. You can control the closing speed as you wish. Easy to use. Installation and quality standards – the door closer comes with a detailed installation manual and a clear installation video. Installation was easy and straightforward. Wide range of applications: This door closer uses a #2 spring and is suitable for doors weighing 20 to 40 kg and with a door width of 750 to 850 mm. The automatic closing mechanism is suitable for top-opening doors. It is suitable for right- and left-hand opening, wood, metal, residential and commercial doors, exterior/interior doors, fire doors, hotels, apartments, and warehouses.