8 inch Air Duct Grate Screen (1 Pack)

Seems to be a 3D-printed product, pretty neat that they can get the grid of fins so fine like this. This is made with a diameter that only fits inside 8-inch duct, it will not fit around it and will not even fit onto 8-inch inside couplers. An 8-inch hose clamp will be needed on the outside of the duct to close any gaps.If you need to attach this to an inside coupler or a fan that also only fits inside duct, you can use an AC Infinity 8-inch rubber noise reduction coupler. They're a bit pricey but work perfectly and come with two hose clamps.I am using this as a pre-filter for a fresh air intake into an 8-inch filter box. In my case, I needed to use a rubber collar to get this to work. It would be helpful if the manufacturer offered this in a larger size that could fit OVER 8-inch duct. I would buy several more.It works well as a pre-filter, but does require frequent cleaning. Outside air has so much dust and debris it clogs up fairly quickly. A version with larger spaces between in the grid might be helpful because it would require less cleaning. This one keeps the air filters inside my filter box cleaner though, so it's give or take either way.