AXEON MBR-4520 DI Filter Cartridge, 4.5 Inch x 20 InchAXEON MBRSeries Cartridges utilize our 2. 5" or 4. 5" diameter configurations that fit most standard size filter housings. AXEON MBR Series Cartridges feature a Gel Poly Styrene Cross linked with DVB mixed bed resin. The DI resin used in these cartridges has been specifically developed to reduce total dissolved solids, including calcium and magnesium carbonate. AXEON MBRSeries Cartridges provide a solution for a variety of applications that need the