Features Reverse current damper A duct connection equipped with a reverse current damper device to ensure stable airflow without leaks. Premium Material The use of high quality ABS material and sturdy structure ensure excellent durability for long-lasting use. PERFECT FITMENT: Perfectly fits for 6 inch flex or plastic pipes on dryers, exhaust fans, etc., useful and reliable. Single Way Flows: Allows automatic switching, this return blocker allows only 1-way flow as well as damping. EASY TO INSTALL Designed to have a light weight and compact size, the installation can be completed quickly in minutes. Specification: Item type: non-return damper. Product size: 6 inches. Material: ABS Driving mode: automatic switching. Flow Direction: One Way Package list: 1 x non-return damper Package List 1 x Backdraft Damper