Isn't tap water good enough?

Maybe. Throughout the Australia, NZ, USA, Canada and Europe, tap water is generally safe. High levels of chlorine kill pathogens (germs) so you don't get sick. But most of these countries allow drinking water to contain trace amounts of a wide range of impurities - certain heavy metals (lead, arsenic, iron), industrial and pharmaceutical chemicals, elements you can taste (chlorine, copper). The activated carbon used in GRAYL® filters has been proven to greatly reduce many of these contaminants.

The result: great tasting water and one less thing to worry about.