The Sawyer 2 Liter Complete Water Treatment System is an extremely simple and fast way to filter water in the field. We even color coded it to make it easier. Fill the grey reservoir bag and fill it with the water you want to be filtered, then hang the grey reservoir above the blue one and let gravity handle the rest! It can filter up to 2 liters of water in a minute and a half. You can also fill your water bottle up directly from the filter if you don’t want to bring the blue reservoir bag along with you. Check out the video above to learn more about the Sawyer 2 Liter Complete Water Treatment System.