The cone shown in other figures fits into the top of this water bottle
Stellenbosch University's Hope Project has produced a disposable water filter shaped like a tea bag. When placed in the neck of a water bottle, the bag removes all harmful chemicals and microbes. Each bag cleans one liter (1.06 quarts) of water, so a lot will be needed to make any significant impact on water-related health issues globally. However, when compared to competition such as the LifeStraw or LifeSaver, it would seem to be a cost effective solution. The product is currently being tested by the South Africa Bureau of Standards.