98-03 YAMAHA XVS650A: MAC Performance Fat Stakkers Exhaust System (2-1/4") At MAC, they are dedicated to building products that meet strict quality standards. They follow exacting guidelines during manufacturing in order to insure that you receive a quality, reliable product every time. Stack up style and performance on your bike. Aluminized steel with chrome coating. True double-walled headpipes help prevent blueing.