The DT-1 air filter is manufactured with the highest quality bonded dual layer foam available. DT-1's world class foam technology delivers maximum airflow while still maintaining engine protection. The DT-1 filter comes with a super seal base which eliminates the need for grease. DT-1 air filters come standard or pre-oiled. Our pre-oiled filters are oiled with the highest quality bio-degradable filter oil. Please specify Bike year, make, and model in notes.