Hinge Kits, Fits Square Base Size 19 in, Compatible Grainger Part Number 16D522, 16D523, 20FT09, 20FT10, 20FT11, 20FT14, 36WG76, 48C179, 48C180, 48C181, 5DVN6, 5DVN8, 5DVP0, 5DVP4, 5DVP6, Material Galvanized Steel, Includes Curb Cap Channels (2), Curb Mount Channels (2), Hardware Kit, Reinforcement bracket, For Fan Type Downblast Fans, Upblast Fans, For Fan Mounting Type Roof Mount, Container Capacity Not Applicable, Standards AMCA, NFPA 96, UL 762