This is Nalgene's most popular bottle. Its narrow mouth opening makes it easy to drink from. Features: --Attached loop-top so you can easily clip it to your pack. --Screws on and off easily. --Printed graduations. --Dishwasher safe...make sure the top does not touch the heating element, or it will melt. --Made from Eastman Tritan copolyester that is manufactured w/out Bisphenol A (BPA). --Extremely durable. --Non-Leaching. --Resistant to staining and retaining odors. --Made in USA.