Ductless Flue Extension In Stainless Steel For Ew48 Series Chimney Range Hood Optional Flue Extension In Stainless Steel For Use With Broan? Elite Ew48 Series. Flue Can Be Used In Ducted Or Non-Ducted Applicatons To Suit Your Needs. The Optional Flue Extension Accomodates 9' To 10' Ceiling Heights.