18.5 oz (550 ml). Filters as you drink. BPA free. FDA approved. Great taste. Recycled. Make water better. Bobble is a revolutionary product that takes care of the planet, keeps your body hydrated, your wallet fat, and your taste buds satisfied - all while looking good doing it. Bobble will change the way you drink. Facts about your bobble filter. Better tasting, healthy water at a fraction of the cost of bottled water. Bobble's carbon based filter removes organic contaminants from regular municipal tap water and meets or exceeds NSF International Standard 42 for chlorine, taste and odor reduction. For best results we recommend changing your filter after 2 months or 40 gallons/150 litres. CPSIA certified. 100% of this bobble is proudly made in the USA, low carbon footprint.