Hon&Guan 3 Inch Duct Connector Flange, 3 Inch Duct Collar Dryer Vent Connector for Heating Cooling Ventilation Vent System, Black.

4" pipe cover

I have an xTool laser engraver with the xTool enclosure. It came with a 3 inch fan but, it get's dirty quickly and doesn't move enough air so I bought this connector and an Infinity 4 inch fan. I attached this connector to the enclosure and the fan to the other side of this connector. I have a flex hose attached to the fan motor that directs the smoke and fumes outdoors and it works great.

I decided to try to make some (feral) cat shelters out of used coolers. I bought the 4" and 5 " covers to line the entry/ exit hole. I needed a 6" too, but decided to try something else for the 6" hole. The 4" was really too small for the cats and did not end up using it. I wanted the tube to stick out to help create a bit of a rain barrier. The red Igloo cooler was so thick that the tube was almost flush with the wall, so it didn't matter which way it was installed. I installed it with the flange on the outside to cover the unsightly, rough edges of the hole. The blue Coleman cooler was thin enough to get the tube to stick out a bit. I was hoping this would be a nice tight fit, but it was pretty loose. I didn't want the ugly look of duct tape. I tried some electrical tape around the rim, but it didn't stick. Someone had recommended using calk to seal the hole, but one of the instructional videos said their cats don't like the smell of the calk and won't use the shelters. I really like that this had the screw holes, and I didn't have to worry about messy calk. Low price and screw holes were great for my project.

Not much to say about this. It is as advertised. Heavy gauge plastic which will stand up to a hose clamp. The 4" vent hose that I selected fits snugly and delivery was quick. Nothing bad to say.

Very pricey @ $10.99 for just one, considering you can buy 4 identical ones of another brand for $16.99