GoFiltr Alkaline water infuser turns your ordinary water into natural mineral spring ionized antioxidant alkaline water with up to 9.5 pH in minutes. Just drop it in your bottle and keep refilling. GoFiltr Alkaline infuses water with vital minerals, magnesium, potassium and other electrolytes. It fits any reusable water bottles with 1″ opening or wider – glass, plastic, metal, copper, stainless steel vacuum insulated bottle for those who love keeping their water cold, flask, pitcher, hydration pack, works best with 12, 16, 18, 24, 32 and 40 oz bottles in size. Can be used with pure filtered water, tap water, reverse osmosis water, sparking water, and turning your distilled water into spring mineral water. Very portable, great for travel, sport, gym, yoga or any daily life routines. Lasts up to 3 months or 750 refills – only 4 cents per refill/bottle of all-natural alkaline water. Download free mobile app available for IOS and Android to track usage and refills. All GoFiltr cartridges made in sunny California, USA.