Stainless Steel Door Hinges: The hinges are made of stainless steel materia,designed for industrial, commercial & residential doors, especially in marine & other outdoor applications,Stainless steel for maximum corrosion protection. Automatic closing: The inner and outer doors are designed to automatically rebound and close the door, with adjustable tension, making it quiet, stable and noise free.Ideal for any door that gets regular use, whether at home or in a busy commercial space. Extremely durable?Our heavy duty stainless steel hinge has good load-bearing,such as wood, metal, interior, exterior, residential and commercial doors.