Constructed to withstand humidity, high velocities and turbulence, the EFS rigid pocket filter is for use in areas where space is limited. Designed for use with final filters, this product increases filter efficiency, and lengthens the life of the final filter. Engineered for double use, this filter works as both a moisture coalescer and particulate filter. The product coalesces moisture upstream of the final/static filter. The filter element is free of metal parts, eliminating the risk of corrosion and punctures and the polyurethane header ensures a leak-proof bonding of pockets to header. Available in G4 and F5 efficiencies, the filter is comprised of 100 percent synthetic structured media. Advanced Filtration Concepts.