Blauberg UK Round Ceiling Vent Diffuser Extract Grille Valve with Retaining Ring (100 mm 4" Dia), White, 100mm

I purchased this product to fill an old tumble dryer output 100mm which led out the house causing a cold to enter the house. Vent closes completely perfect for the job. It came well packaged and quickly to Amazon locker. Easy to install simply push in, nice and snug and neat. Highly recommend.

Well made and fit snugly. Before install make sure you set the nut on the inside to desired height as after install only way to access but again is through loft removing ducting.

This looks good when fitted and is a neat option. We previously had a square cut grille which collected dust, whereas that shouldn't happen with this item.You can adjust the size of the gap between the duct and the 'mushroom' cap, but I am not sure I can tell any difference in terms of extraction rate between having it wide open or closed up a bit.The only bad point about this is the fitting. There is a collar that screws into the roof and then the rest of the duct including the throat that protrudes into the roof, locates on this collar. But, you have to get your collar fixing holes exactly centred around the 100mm hole for the throat, or the whole thing won't line up. Mine wasn't perfectly aligned as I was replacing an existing vent and it was very hard to get it onto the collar. This might not be such an issue with a fresh install.(For comparison, the one that we removed had the fixing holes in the main body of the vent. This would make it easier to align the duct hole and the fixing holes. There was a clip on collar to cover the fixing screws once the vent was in place. This seems to me like a more sensible solution.)

Excellent, well made bit of kit. It isn't airtight if that's what you are looking for (as we were) but you can use draught tape to achieve the same effect.

Quick and easy to fit. Adjustable. Sleek design. Good value. Very pleased with it

These vents look good, and can be adjusted depending on outside temperature or time of year, or frequency of use of shower room - in these covid times our guest bedroom shower has had no use so I've reduced the ventilation.

Dead easy to install. Plenty of air volume adjustment. A bit cheap plastic but once is on the ceiling you can’t see it.

Very nice quality vent, that can be adjusted for airflow. The only negative is the fitting method, which isn’t perfect. It relies on spring steel ‘blades’ protruding sideways from the housing forming part of the cover, gripping against the separate body which is installed into the ceiling. There is a foam seal that sits around the vent where it meets the ceiling and the steel blades do not grip strongly enough to hold the vent against the push of the seal. Not difficult to overcome but design could so easily be improved.