3 pack - Hydronix spc series 2.5 inch x 10 inch 30 micron polyester pleated cartridges are manufactured from durable polyester to provide you with a superior pleated filter that is washable, reusable and durable. The spc series pleated filters are chemical and bacteria resistant, have a great dirt holding capacity and extend the time between filter changes. Hydronix spc series polyester pleated cartridges are suitable for a variety of uses and can be used in residential, commercial and industrial applications. The polyester media is pleated around a polypropylene core for added strength and the ends are immersed in a thermostat setting vinyl plastisol. Embedding and sealing each end of the Pleat in this fashion fuses the three components together forming a unified end cap and gasket.