I love that it muffles the noise of the vacuum cleaner motor when it's in our garage. But it doesn't dampen it enough. However, since the muffler shouldn't cause any back pressure that could overload the engine, it's only as good as it needs to be. The muffler consists of a foam rubber tube that lines the inside wall of a PVC cylinder. I calculated generously that this almost halves the exhaust noise. If the foam rubber was a bit thicker, maybe it could make a difference. However, when theβ¦