Silver Series systems are fitted with silver bands Natural 6061 Aluminum inlet/outlets, and a black Magnesium end cap Adding this high performance Silver Series exhaust system will help you gain additional horsepower and increase torque while lowering the over-all weight of your bike V.A.L.E. slip-on/full exhaust systems and flange-on systems feature CNC machined aluminum inlets and outlets. These special designs provide for ease of maintenance as well as simplified construction, which is what a premium performance product is all about!