High quality 2.5”x10” pleated polyester filter cartridge to ensure the best possible protection of the high pressure pump and membranes. When its time to change filters, they should be replaced with new filters, so it is recommended to have a stock of spare filters handy for any voyage. 20 micron filters are used on Ventura MPC systems, the Newport series, LB 400 and LB 800 series, as well as older models such as Catalina 300 systems.