This is the duct work piece that connects the heater core to the cross air cabin heater vent duct box under the glove box from a 1958 Cadillac. This will fit all 1957 & 1958 model Cadillac's, including Eldorado ( except Brougham ) but please verify that it is correct for your application before purchasing. This runs from the heater core box in the drivers side firewall, through the dash around the gauge cluster, to the cardboard box mounted under the glove box. Comes as shown, Sold As Is. Please let me know if you would like any other info. Thanks.