The Straightline Performance Yamaha Mountain Max 800 Ultra Lightweight Stainless Steel Muffler is constructed entirely from premium polished stainless steel and delivers an impressive 14-pound weight savings over the factory muffler. Dyno tested and field proven, this direct bolt-on performance muffler improves throttle response, handling, and overall performance while providing a deep, refined exhaust tone. Precision TIG-welded and backed by Straightline Performance's guarantee against weld failure under normal riding conditions, it's built to deliver years of dependable performance.