Flange for air duct ,phenolic, FSK facing,HVAC glass wool blanket ,Duct wrap, flexible air duct Duct board ,alu glass duct. 1) Designed for the conjunction of air conditioning system (Phenolic aluminum Foil Compound air duct system and fiber glass board air duct system). 2) Material: PVC.3) Color: White/Grey/Cream White etc. U Flange for air conditioning system