The Twin Air Pre Oiled Fire Retardant Air Filter has the same treatment that the factory race teams receive and. Are 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 faster to change out the filter and get back on your bike for more great days off.