MSR has stopped making the Marathon 205/Marathon EX Ceramic Element. The Marathon 205 Ceramic Element was our very first ceramic element, introduced in 1996, and it was part of the first-generation WaterWorks and MiniWorks micro filters. Production ended in 2002. In 2003, we replaced the Marathon 205 with the Marathon EX Ceramic Element, which offered 25% faster filter rates compared to the models made before 2003. The Marathon EX Ceramic Element was discontinued in 2008 and has since been replaced by the current MiniWorks/WaterWorks Ceramic Element.
The MiniWorks/WaterWorks Ceramic Element can be used as a replacement for both the Marathon 205 Ceramic Element and the Marathon EX Ceramic Element. You can find replacement cartridges available for purchase on our website and at most major outdoor gear retailers. The cartridge comes with all the O-rings needed to make the micro filter work.