Hindle designed a noise reducer insert for Hindle EVO Megaphones with a Classic Tip. This new version quiets down the noise even further without compromising power. In fact- with Hindle's testing- they have found that some models produce more power with the noise reducer installed. A great option for race tracks where there is a maximum decibel level or if you are riding on the street and wanting to quiet down your muffler even more.Easily inserts into the end cap of the muffler and can be removed when not needed. Only available in one size (fits ALL Hindle Evolution mufflers and Hindle Evolution megaphones).Please refer to installation instructions for proper installation.