Clearly Filtered Stainless Steel Bottle Replacement Filter Our unique filter formulation allows for the most robust tap water filtration on the market. Simply screw the filter onto your existing cap/straw and filter any tap water as you suck through your straw Made with Affinity Filtration Technology for up to 99% removal of Fluoride INSTANTLY. Our unique filter formulation allows for the most robust tap water filtration on the market. Simply screw the filter onto your existing cap/straw and filter any tap water as you suck through your straw. Remove up to 99.99% of most chemicals and contaminants including Lead, Mercury, Herbicides, Pesticides (including Glyphosate - the cancer-causing chemical in Round-Up), and up to 99% of Fluoride. Great For Saving Money Will save you hundreds of dollars by replacing overpriced bottled water Filters typically last the average user 25 gallons (or 4-6 months use). Replace filter every 6 months or when flow becomes restricted. Bottle holds approx. 27oz of water. To filter the water you must sip water upright through the straw assembly