Nalgene s 24oz On The Fly bottle has a leakproof loop top that 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 Sustain bottles are made with material derived from 50 plastic waste Each bottle is created from resin powered by next generation recycling technology that transforms plastic destined for landfills into high performance bottles Specifications . Weight 0 2 lbs