KEEP OPEN IN 90~180 DOOR OPENING AREA - If your opening ane is more than 90, this door closer can keep the door open at any ane. You don& 39;t need to use an external force or a door stopper to hold the door open. This is the best option if you like a well-ventilated space or need to move your cargo around a lot. You just need to pull the door within 90 and it will close automatically. HIGH QUALITY AND ADJUSTABLE SPEED - The hydraulic door closer is made of high quality aluminum alloy. It can silently close your door automatically. Improve your quality of life. You don& 39;t have to yell "close the door" as often anymore. The door closer has 2 valves that independently control the closing and latching speed. You can control the closing speed as you like. EASY INSTALLATION AND QUALITY STANDARDS - The door closer comes with detailed and clear installation instructions and installation video. It will be an easy and smooth installation. Hydraulic door closers are CE, UL, 3C certified and fire tested. Manufactured according to EU production standards" Widely used - Size 2 door closer spring for door weight 25-45 kg and door width 750-850 mm. Self-closing is suitable for left and right doors, wooden doors, metal doors, residential and commercial doors, external/internal door closers, fire doors, hotels, apartments, apartment buildings and warehouses."