It seems to be designed to reduce turbulence as air passes in and out through the soundhole, but in doing that, it adds mass to the guitar top.
As such, it will make a difference to the frequency spectrum of the sound. Whether that is an improvement or not is likely to be a matter of opinion. It is worth bearing in mind that an acoustic guitar is not a trumpet. Many components are sound emitters in addition to the sound hole.
Anyone who tries to amplify the sound of a guitar by sticking a Mic next to the sound hole will soon learn that the boomy tone from there is not, by any means, the true sound of the guitar.
The way in which the vibrations of the strings are 'coupled' to the surrounding air to create sound is highly complex and varies with both pitch and volume as well as from one string to another.
You guitar will sound like a different guitar, but it will cost you thirty dollars to find out whether you like it.
My advice would be to buy it for a guitar you don't like, and leave alone a guitar that you do.
Cheers
Dave