Hinge Kit Fits Square Base Size 42 in Compatible Grainger Part Number 3GY69 3HFL8 4YY10 5EFH9 Material Galvanized Steel Includes Hardware Kit Reinforcement Angles Retaining Cable For Fan Type Downblast Fans Upblast Fans For Fan Mounting Type Roof Mount Container Capacity Not Applicable Standards AMCA UL 705 For Use With Dayton Roof Mounted Centrifugal Downblast Ventilators Having a 42 in Square Base