NATIONAL MFG/SPECTRUM BRANDS HHI N351-031 Spring Door Hinge, 4-Inch, Stainless Steel The product is 4" Spring Door Hinge - Adjustable Tension and Closing Speed - Cold Rolled Steel Construction - Fits Standard Hinge Cutout - 5/8 " Radius Round Corners, Hinge Is UL Approved For Fire Doors - Stainless Steel Finish Closing Speed Is Adjustable The product is manufactured in China