Wide Wide Mouth Flex Cap With its double-wall vacuum insulated TempShield technology, liquids remain hot up to 6 Hours, and cold up to 24 Hours All C BPA-free plastics & 18/8 stainless steel food-grade stainless steel Thanks to the proprietary powder coat, your bottle stays slip-free making it easy to Go wherever you do Fits most backcountry water filters for all-day, or all-weekend, hydration