Product review (5 stars): Works great! When it came in a small box I ...
Works great! When it came in a small box I was surprised. I didn't read the instructions and so I don't know if it is mentioned or not about how to install it. But please note that the circular metal ring that comes with it is a clip and you have to push the two upwards bent ends towards each other to make them open up and insert into the pipe duct.