Nalgene's leak-proof loop-top swings open wide to reveal a contoured, high-flow drinking spout that's easy to fill at the fountain or sink. One-handed push button for easy open/close; locking bail for ultimate insurance against leaks. Dishwasher safe. BPA Free. Nalgene offers these bottles in a 24 oz./136.1 gram version and a 32 oz./155.9 gram version.