Nice! Is this for like basement growing to help filter and possibilities of powdery mildew? Probably helps keep dust out of the tent as well. I leave my 3 mesh vents open and that catches bigger particles but this would ba good idea to close the vents off and use this to insert in my 4 and 6 inch holes. My tent is in its own room in my house so air is pretty clean. Dust is biggest issue. Seems kinda simple but I bet it would save my life span on my inline 6" fan, carbon fiber and other equipment including my led.gray idea bro, might try this when I set my tent up in next few days. Upgrading from a2x4 to a4x4