1.Floor Spring with accurate position 2.Throught 500,000 times test 3.quality anti-icing hydraulic oil 4.5 years warranty NameFloor Spring , Floor Hinge , Floor Closer , Floor Door CloserSpecification :Single Action , Doubld ActionwarrantyFive years guaranteetestthrough 500,000 times test ,ensure the best quality Different design,suitable different market demand : The popular type: Function ...