FITMENT??fit for predator 301cc 420cc 13hp 15hp Hond* GX270 GX340 GX390 mini bike go kart golf cart mud boats lawnmower water pump pressure washer powered OHV engine.Fitment model Compatibility:Predator 301cc(8hp),420cc(13hp) Engine,Hond* GX340(10.7hp) GX390(11.7hp) 389cc EngineHIGH PERFORMANCE??it’s the predator 420cc performance parts upgrade header exhaust pipe kit. It’s a simple job to upgrade go kart engine mini bike exhaust pipe,and let the exhaust flow more smoothly to promote more power.HIGH QUALITY AND EFFICIENT HEAT SHIELD PRETECTION??it made of heat resistant silicone,which can be used for long time and won’t melt.The heat shield spacer can withstand 2192?Hand prevent burns from the hot exhaust pipes during riding.It is made of high quality materials and it can play a protective role.ROAR AND SILENCE?? if you like pop and loud sounds that want to make your GX390 engine sound like a little beast. You can add the predator 420cc exhaust pipe to amplify the motorcycle roar and you’ll