TWIN AIR CRANKCASE BREATHERTWIN AIR 158997, Dry breather filter with intake. Crankcase breather filters allow the crankcase to maintain consistent pressure within the engine combustion process Plug in style breather 10mm thick foam 12mm diameter intake (Where the hose fits onto) Mounting point hole to secure the breather to your bike Part No. 15-8997.TA 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.