I cut the top off of a 2 liter soda bottle and marked the bottom on the side at the 1 liter mark. I use this to scoop water from streams and lakes and to use as a container for stirring with the Steripen UV wand. The container weighs less than an ounce and the rim will bend to form a pouring spout. It fits over the top of my rolled Thermarest ProLite 3 for carrying on the trail. I also use it to hold a bit of extra water around camp (1.4 liters to the brim); a freezer bag fits over the open end to keep floaties from getting in.