Getting ready to install a dryer? The Lambro Premium RigiFlex Duct with 2 Clamps is a Ul certifed clothes dryer transition duct that’s ideal for all electric and gas clothes dryers. It has a 4 in. diameter and is 8 ft. long. The patented dryer duct with its all metal design is both flexible and rigid’ yet it will not collapse and provides maximum airflow with less lint buildup. Buy this duct with confidence-it is dryer manufacturer recommended.