All Silverline stainless steel diesel systems are supplied with a highly polished muffler featuring polished welds to provide a seamless appearance. With a free-flow design, the strategically placed louvers provide sound deadening control for a more pleasant in-cab ride while still providing the deep, rich sound of the diesel engine during acceleration.Systems are offered in single and dual 4â? and 5â? configurations, all engineered for optimal performance and perfect fit. Silverline diesel truck systems are available in T304 and 409 stainless steel, or aluminized steel, are equipped with pre-welded hangers and come ready to install with all necessary hardware. In addition, all T304 and 409 systems come complete with a T304 5 double wall tip!