Double-wall bottle keeps water cool and reduces condensation. Re-engineered cap and bite valve provide faster flow and enhanced durability. One-Hand Flip, Bit and Sip: No tipping required (though possible, just remove the straw). Quick Flip Close: The articulating stem lets the Big Bite Valve fold flush to bottle cap when not in use so it stays clean. All parts are top-rack dishwasher safe. Prices may vary.