feature: Reduce buffer speed and protect your door Automatic door closing, more convenient Reduce noise when closing doors doors Installation tips: 1. Adjustable tension - adjust the closing force of the door - insert the hex key and turn it clockwise or counterclockwise. 2. A door closer should be installed in the middle of the door (if only one door closer is installed) 3. The door and door frame should be kept on a horizontal plane and the drop should not exceed 3mm. 4. If you want to use this product, you must have a door frame, and the width of the door frame must be more than 3 cm. 5. If it is a heavy door (weight 40 kg), two door closers should be installed, preferably one above the other, so that the door can be closed normally. Whats included: 2 x door closers 8 screws 2 x hex keys