All metal dryer hook up kit. Semi-rigid duct is UL 2158A labeled and approved for safe dryer venting. Meets and exceeds all dryer manufacturers instructions and requirements. 35% thicker than standard non UL duct and is totally noncombustible. New manufacturing technologies incorporated into this duct also allow for easy rotation, therefore adding durability during installation. Metal elbows are flame resistant for a safe and long lasting connection. Designed to achieve tight 0 to 90 degree turns which saves space while still maximizing airflow and are crush resistant. Kit includes: one 4″ x 8 UL 2158A listed and marked semi-rigid aluminum duct, two attached all metal heavy duty elbows, and two 4″ metal galvanized worm gear clamps.