auto close hinge,Multifunctional hinge,3-in-1 door closer hinge.Easy opening and closing,shock absorbing. auto close hinge1.Specifications Shaft DiameterΦ ... 50 million or more circles)1)special-made aluminum, high quality steel or stainless steel, advanced hydraulic oil (pour ... technology ensure first-class quality.3), for the parts from producing to finishing, high-precision testing equipments used, ...