Nalgene has taken some of the best bits from their classic bottles to create the OTF. The leak proof design and single hand operable lid makes it the ideal work out bottle. The OTF snuggly fits in a bike bottle cage or a car’s cup holder. All Nalgene bottles are BPA free and the OTF is made from the legendary Tritan material, so you taste what goes into your bottle, and nothing else.