Part No. 23-811 HONDA CRF 450R � 2019. MX Radiator Sleeve TWINAIR 141177759SL07 The TwinAir Radiator sleeve is a nylon coated, glass yarn material that fits over the radiator louvers so no dirt, sand, or mud can stick to the radiator, clogging the radiator, causing overheating. The TwinAir radiator sleeve is easily installed by removing the plastic radiator louvers and sliding the TwinAir sleeve over the louvers and re- installing on the radiator. , Majority of our listings are for a direct replacement for your original part. Our parts are made of quality and are designed to meet or exceed the original OEM Standards. Our products are often a cost effective alternative to genuine OEM Parts. Please note: the models of bike we state in our listings are for general guidance only. Please make sure this item will fit your bike before purchasing. Also, we cannot guarantee fitment to any non-UK models.