FOR ST MODELS PLEASE INCLUDE YOUR BIKE ON THE CART PAGE FOR A FREE BAG MOUNTING BRACKET 4.5” HIGH FLOW PERFORMANCE ROLLED CONE MUFFLER WITH STEPPED BAFFLE FROM 2 ¼ TO 2 ½ INCHES. INCREASES BOTTOM TO MID RANGE TORQUE AND HORSEPOWER ON ALL MOTORS. TUNED PROPERLY CAN ACCOMMODATE 88" TO 143". 065 STAINLESS STEEL HEADERS, STEPPED FROM 1 ¾” TO 1 7/8” TO 2” AT THE COLLECTOR HAND TIG WELDED FROM TOP TO BOTTOM MACHINED STAINLESS STEEL HEADER COLLARS 18MM O2 BUNGS WITH 12MM ADAPTERS, ALLOWS FOR STOCK OR AUTOTUNE SENSORS COMPLETE HARDWARE KIT WITH EVERYTHING YOU NEED TO MOUNT IT UP