Preheat Duct Adapter for lower cowl for secure attachment without risk of scratching paint. Pull down wire releases duct. Internal spring wire ensures long life. This duct is supplied as printed and the user adds the fiberglass shown in green and the .125 dia wire. Holes are in place for the wires. Fits standard 6 inch flexible dryer duct and works well with inexpensive standup electrical heater. Material is ABS. Fiberglass and wire are not included. The one is the photo has been operating for 3 yrs.