Hi-Power 409 mufflers offer a cost effective solution for your sports muffler needs. The rear section is made from SUS304 grade stainless steel for a high lustre finish and the piping section which is not visible once fitted is made from coated SUH 409, reducing the cost. SUH409 has other benefits such as being more resistant to thermal expansion and improved acoustic properties. SUH409 has the ability to absorb more sound than SUS304 which allows Hi-Power 409 mufflers to have a straight through design without fear of excessive noise.