Specs Materials The Pentek R30-478 Pleated Polyester Water Filter Cartridge is manufactured from a durable, non-woven and reusable polyester fabric suitable for a wide range of filtration uses. The media is pleated around a polypropylene core for added strength and the ends are immersed in a thermo-setting vinyl plastisol. Embedding and sealing each end of the pleat in this fashion fuses the three components together forming a unitized end cap and gasket. The overlap seam is sonically welded to reduce internal bypass improving filtration efficiency. The Pentek R30-478 Pleated Polyester Water Filter Cartridge removes particles to the 30 micron level.