1. Fit Models: Exhaust muffler kit replacement for Stihl 064 065 066 MS640 MS650 MS660 chainsaws and you need buy it with carefully know the type. 2. Main Function: Exhaust muffler set with high quality parts are used to reduce the noise generated by the chain saw engine and easy to use. 3. High Quality Material: Exhaust muffler kit is made of high quality metal material, durable and wear resistant, and has a long service life. 4. Good Performance: Exhaust muffler kit with professional manufacturing, superb craftsmanship and high precision help to provide the best performance. 5. Complete Package: Kit includes 1 Exhaust Muffler, 1 Muffler Gasket, 2 Spline Screws M5x6, 2 Spline Screws M5x16, 2 Spline Screws M6x