These Dynatech auger-style muffler inserts are designed to slide into your round tube piping. Auger style inserts are one of the best ways to reduce the most sound without reducing the power. These inserts do not reduce the area of the exhaust system while still spinning the exhaust 360 degrees to break up the sound. They weigh only 1 lb. and offer a 6-7 dB reduction over standard straight-through pipe. The inserts are manufactured from quality materials and install easily with simple hand tools.