The AirDog Replacement Fuel Filter FF100-2 is a direct replacement Fuel Filter for your AirDog Fuel System. The life expectancy for the AirDog Fuel Filter could be up to 25K miles or a year. However, those figures can change drastically depending on fuel quality. We run the 2 micron filter in warmer weather conditions. For colder conditions or climates use the 10 micron for better fuel flow.