Ready-to-Use air filters are made of fused dual-stage, open-cell foam. Open pore outer foam layer allows for maximum airflow, while the more dense inner layer foam ensures filtering protection from dirt, fine sand and dust. Dual-stage design resists filter plugging and airflow blockage. Pre-oiled with Maxima FFT the worlds best and most effective air filter oil. Packaged ready-to-use.Ready-to-Use air filters are made of fused dual-stage, open-cell foam. Open pore outer foam layer allows for maximum airflow, while the more dense inner layer foam ensures filtering protection from dirt, fine sand and dust. Dual-stage design resists filter plugging and airflow blockage. Pre-oiled with Maxima FFT the worlds best and most effective air filter oil. Packaged ready-to-use.Ready-to-Use air filters are made of fused dual-stage, open-cell foam. Open pore outer foam layer allows for maximum airflow, while the more dense inner layer foam ensures filtering protection from dirt, fine sand and dust. Dual-stage design resists filter plugging and airflow blockage. Pre-oiled with Maxima FFT the worlds best and most effective air filter oil. Packaged ready-to-use.