HMF Engineering is the world leader in performance exhausts for ATV and UTV this listing is for a HMF competition series elliptical slip on exhaust system and HMF Fuel controller/EFI optimizer to fit 2009-2016 Yfz 450 R 2010-2011 Yfz 450 X HMF PART NUMBER 141413706186 he exhaust includes 3 interchangeable inserts to tune sound decibel levels and power delivery to your liking. The optimizer comes with pre loaded map and adjustment options to maximize your machines power output and efficiency! This combo offers a significant horsepower gain and huge weight savings with simple installation. Item is brand new in original manufacturers packaging with full manufacturers warranty! Make and offer and make it your today! Free shipping!