Can hold door weights up to 40 kg - Pair of door closers (up to 20 kg - 1 door closer). 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 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 required fixings. Come with 2 door closers. Suitable for different types of doors 2-piece automatic door closers, silent spring door closers, adjustable tension It is spring-loaded with adjustable tension and can be used on left or right opening doors up to 40 kg. Features: Reduce buffer speed, protect your doors Auto to close the door, more convenient Reduce the noise caused by the door closing IMPORTANT NOTICE: 1..Adjustable tension - Adjust the door closing force - Insert the hex wrench