The Twin Air Pre Oiled Air Filter has the same treatment that the factory race teams and OEMâ€s receive, the Twin Air Pre Oiled Air Filter is pre-oiled with Biodegradable foam filter oil that provides ultimate consistency in pore coverage. The Twin Air Pre Oiled Air Filter is designed to catch all the dust and debris and allow efficient air flow giving your machine better performance. The Twin Air Pre Oiled Air Filter is pre-oiled for your convenience making it easier and fast to change out the filter and get back on your bike for more great days of riding.