【Size】Made of galvanized steel. Adapts 8 inches to 6 inches. Round Ducting Adaptor 【Widely Application】Designed for bathroom extractor fans, HVAC systems, inline ventilators, cooker hoods, tumble dryers, hydroponics, kitchen. 【Adventages】Maintains airflow efficiency by creating a connection between two different sized duct openings. 【How to Use】The solid duct reducer or increaser can be used when connecting two different solid or flexible ducts or ducts to ventilators, 8 to 6 inch, or vice versa. 【Easy to Install】Put it in the two ducting, easy to install the air duct reducer.