The DT-1 ATV air filter is manufactured with the highest quality bonded dual layer foam available. DT-1’s world class foam technology delivers maximum airflow while maintaining critical engine protection. The DT-1ATV filter comes with an exclusive 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 flame resistant bio-degradable filter oil.