Give your GeoPress a boost! In April of 2023,GRAYL redesigned GRAYL's Cartridges to accommodate a One-Way Valve. It's a significant upgrade that includes a new "core" plus "flow channels" making it possible to add electrolytes, drink mixes and other flavoured liquids into GeoPress.

A feature no other drink-thru filter bottle can deliver, the GeoPress One-Way Valve allows electrolytes and sport drink mixes to be added to clean purified water without compromising the integrity of the filter. Also allows a GeoPress to be used with a variety of flavoured drinks such as juice, bubbly water, mocktails and cocktails.

Only compatible with 2nd Generation cartridges first sold in April 2023 that include a new "core" and "flow channel" design (horizontal vents). 1st Generation cartridges are not compatible with the Drink-Mix Valve.