Plagued for ages by my acoustic booming on stage, I had to find a solution. A friend suggested a more expensive item like this to me, but, I said, what the heck, I'll try the cheap one first, if it makes a difference I can always get the more expensive one afterwards! So, it arrives with my next order from Thomann, I plonk it into the soundhole, and strum.......hey! where's the sound gone? Well of course it's gone, I've just blocked up the soundhole, haven't I? Anyway, off to the gig, first time ever I could turn up the acoustic, no booming, just a good solid full sound, all night long. I'd recommend this to anyone, just take it out (simple to do) if you're at a completely acoustic gig, or you won't be heard......oh yes, the more expensive alternative? This is just as good as the one in my friend's guitar, and half the price.....how can you lose??