calimaero® HWG 4" Dryer Vent Cover Outdoor Walls - Cowled External Extractor Fan Vent Dryer Cover - Robust and Weatherproof Stainless Steel Outdoor Dryer Vent Cover - Fits Only with Metal Pipes

The gasket is 1/4" thick while the cavity is 1/2" deep. Odd until you realize the gasket has a cavity designed for inserting the metal frame (not set inside the cavity). Its a bit tricky to get it to stay in place - once you do, suggest leaving it overnight so it'll stretch a bit. I used gorilla glue in the cavity, then held the rubber in place with 4 large binder clamps until it adhered to the metal edge. Installing over a flat surface it fine, but over bricks, planks, etc., the provided gasket worthless - just get some 5/8" thick rubber and fill that cavity or silicone it in place.The vent itself is rugged and it fits VERY snugly inside a 4" duct. If it's too snug to enter the duct (a problem I had), flatten the 3 holding clips a little. A ring of silicone sealant inside the duct prior to inserting the vent provides a better exhaust seal and eases installation. I also filled teh 1/2" cavity with silicone to firmly seal the vent to the duct. This will force the exhaust air through the port, avoiding moisture build-up against the wall.

The rubber seal that interfaces between the vent's outer edge and the house sheathing did not fit well at all. It was too small, required a lot of stretching and kept pulling off the vent's edges. Not a big deal, I used Tite Seal as flashing which is a metalized flashing with a sticky butyl rubber backing. This provided a supple watertight seal. I add two diagonally crisscrossed 1/4"x1/4" galvanized wire mesh screens to the backside for bird, mouse, and bug control(see pics). Finally, I added an 8" long 6" galvanized round vent pipe with a female to female termination to the back of the vent. This pipe was screwed and silicon caulked to the vent side for a robust air/watertight seal. This pipe extension allowed me to easily connect the male end of the microwave hood vent pipe to the other side of my interior finished wall. Because I am using this for a over the stove microwave vent I found it difficult to locate an 8"x8" vinyl block so I added a J channel picture frame around the vent. Even with these modifications I'm extremely happy with the vent because it's built like a tank.

Very nice quality to replace my old plastic one.

Perfect fit on my 4" duct outlet. Looks good from the outside, but the flap doesn't appear to be strong enough to stay closed on it's own, leading to potential pest and moisture intrusion.

The vent is well made and works perfectly. It was easy to replace the old vent with this one.

Needed a good quality vent to keep the elements & nature from coming in and this product works great and it looks good & fast delivery was awesome.

Great replacement for the plastic vent, which was falling apart after only a few years.Easy to install, even though getting the rubber gasket in place took a bit of an effort.

I bought this to replace an old sun rotted plastic one. It works and fit great. Worth the cost and great quality.