Injen Technology’s Hydroshield are designed to enhance the efficiency of any air filter, including Injen’s SuperNano-Web and our 8-Layer oiled cotton gauze air filters. Injen’s Hydroshield is constructed from a proprietary base media and then treated with a hydrophobic water-repellent. Our Hydroshield is UV resistant, can stop contaminants down to.005″, is puncture resistant, and has elasticity characteristics which helps the Hydroshield to return to the original shape/position after servicing. , Injen’s Hydroshields are engineered to divert damaging contaminants, which can clog your air filter and compromise peak air-flow and horsepower output. Injen’s Hydroshield also extends the time between servicing intervals, reducing costs and improving the overall user experience. Hydroshield – Black, Part No. 1121BLK, 5.0 inch Base x 7.00 inch Tall x 4.0 inch Top.