Usage Tips:Easy to install: Easy to install plastic flaps and sliders on the surface. This spring loaded door closer can be used for doors up to 68 kg as well as left and right doors. Easily adjust the tension of this safety spring door closer. Installation Tips: To avoid excessive tension, adjust about a quarter turn each time and test the door after each adjustment . Excessive tension may cause the spring to bend. Adjust at any time: Two independent valves can adjust the swing motion and the door arm closing mechanism at the same time, so that the force opening and closing speed can be adjusted. [Safe and efficient]: Don't let the door hit you when you go out For your safety, our hydraulic door closers ensure smooth and secure closing. High Quality Material: The lightweight door closer is made of zinc alloy, spring loaded anti-oxidation, anti-corrosion, no rust, stable, wear-resistant, weather-resistant, quiet, safe closing.