These BRITA Micro Discs reduce chlorine and other taste impairing substances while leaving minerals in for great taste. This convenient quarterly pack contains 3 filter discs. To replace just submerge the disc in water for 1 minute then put into the bottle. Each micro disc provides approximately 1 month or 150 litres worth of filtered water with a 50% faster flow than the original BRITA Filter Disc.Fast preparation, just submerge disc in water for 1 minute Each Micro Disc provides 1 month/150 litres worth of great tasting water. . 3 Discs . Wider and thinner shape with 50% faster flow. Fits Fill & Go Vital and Fill & Go Active only.