Katadyn Gravidyn Element. Essential minerals remain in the water. The high performance activated carbon removes unpleasant taste and odor such as chlorine and hazardous chemicals. Replace according to measuring gauge or every 6 months whichever is sooner. Specifications for Katadyn Gravidyn Replacement Filter: Manufacturer: Katadyn Condition: New Color: White Weight: 1 lb Features: Effective against microorganisms Effective against bad taste Suitable for groups up to 5 people Suitable for extremely dirty water For daily or very frequent use Stationary use Package Contents: Katadyn Gravidyn Replacement Filter Katadyn Gravidyn Replacement Filter