Rongyao floor spring can open the door inward and outward. This product is qualified in 500,000 times durability test. All performances and parameters reach national standard. It can be installed in many kinds of wood doors，steel door，aluminum alloy door and reinforced glass door. All key parts of floor spring are made of low alloy steel, with processes of tempering, quenching, fine grinding and assembling finish. The floor spring is filled with high quality and low-temperature hydraulic oil, guaranteeing smooth movement at different temperature，durable and good wear resistance. The floor spring adopts high-quality seals, reliable seal and no oil leak. As the floor spring is composed of several unique assemblies designed purposely by us, you can feel very convenient when you install it.