This diffuses the air coming out of my Ridgid vacuum which doesn't really affect the vacuum's performance but keeps air from getting in my face when I'm sometimes lean next to him. It doesn't act as a silencer to reduce vacuum noise, which is disappointing as it's called a silencer/diffuser. I find it strange that so many people give this thing 5 stars, noting in their review that it doesn't reduce the noise of the vacuum cleaner. I should have read all the reviews and not just looked at the rating. Ridgid should remove the silencer from the description and halve the price.