This Sustain bottle from Nalgene holds 1 liter and has a narrow mouth opening. The bottles are completely BPA/BPS and phthalate-free. The graduation on the side makes it easy to keep track of the day's fluid intake. The bottle neither takes nor adds taste or odor to the drink. The cap is patented and leak-proof thanks to its V-ring seal and can be replaced, there are several colors to choose from. Also available in the size 0.5 liter and as Wide-mouth.