Nuk3y Commercial Grade Heavy Duty, UL rated 4.5 in. x 4.5 in. Spring Hinge (Satin Chrome) PACKED with wood and machine screws. SIZE 4.5-Inches by 4.5-Inches SPRING hinge for automatic self closing doors COMMERCIAL Rated Door Hinge 0.134" Gauge UL LISTED -10C for Positive Pressure Fire Test