TempShield double-wall vacuum insulation keeps contents cold up to 24 hours Insulated Flex Straw Cap is leakproof when closed Wide Mouth opening is ice-cube friendly Color Last powder coat stays clean and colorful Bottle fits most backcountry water filters BPA-Free Dishwasher safe Flex Straw Cap not intended for use with hot liquids Not for use on a stove, in a microwave or freezer