Can hold door weights up to 40 kg - Pair of door closers (up to 20 kg - 1 door closer). (A) One door closer must be installed in the middle of the door (if only one door closer is to be installed); (B). The door and door frame must be kept in a horizontal plane and the drop must not exceed 3MM. Adjustable tension - Adjust the door closing force - Insert the hex key and turn it clockwise or counterclockwise. If you want to use this product, there must be a door frame and the width of the door frame must be greater than 3 cm. Simple to install and supplied with all the required fixings. Come with 2 door closers and hex keys and screws. Suitable for Different Types of Doors 2Pcs Automatic Door Closers, Silent Spring Door Closers, Adjustable Tension, Support up to 40KG, Come with Hex Wrench and Screws It is spring loaded with adjustable tension and can be used on left or right opening doors up to 40KG. Features: Reduce buffer speed, protect your doors Auto to close the door, more convenient Reduce the noise caused by door closing IMPORTANT NOTICE: 1..Adjustable Tension - Adjust the door closing force - Insert the hex wrench and turn it clockwise or counterclockwise. 2. A door closer must be installed in the middle of the door (if only one door closer is to be installed) 3. The door and the door frame must be kept in a horizontal plane and the drop should not exceed 3MM. 4. If you want to use this product, there must be a door frame and the width of the door frame must be greater than 3CM. 5. If it is a heavy-duty door (weight 40 kg), you need to install two door closers, the best installation position is one from top to bottom, so that the door can be closed normally. What's included: 2 x Door Closers 8 x Screws 2 x Hexagonal Wrench Number of products: 2 pieces Color: Silver Size: As shown