lol, yea I had one on my old Pug 306. You fit it to the vac line, its supposed to pulse air into intake stream to create turbulence and produce a better burn. They make a right noise, as the air goes in it vibrated with a loud ticking/rasping noise, you fit a mini pipercross filter to the top of them to suppress the noise. I didnt see any benafits at all, I ended up locking it down as the noise was doing my head in.