To be used with with the Claris Gen 2 head, with quick connect fittings, part #EV433992.
The Claris Ultra M (medium) cartridge is a quick and easy upgrade from the Claris Ultra S (small) cartridge, providing increased capacity in a matter of seconds.
You can upgrade to any Claris cartridge. Here is a link to the Claris Family of Products.
Note: Cartridge & head sold separately although product picture shows both