This silencer needs to be put on top of your 225 kub air extractor. Not the air extractor makes alot of noise mostly but the rapid air movement thats been pushed out. By putting a silencer on to your air extractor, the airflow will first move through the silencer removing almost all noise. Add some suction hose on top of that and your running a very silent air extraction.
So you first have your carbon filter attached to your air extractor and on the other end where the air gets blown out, you have the silencer