Hydro Flask 24 Oz Standard Mouth Flex Cap - WhiteHydration on the go. Stainless steel, cup holder compatible, fits right in your packour largest reusable, refillable Standard Mouth insulated water bottle keeps cold drinks cold for 24 hours, hot drinks hot for up to 12, and holds enough hydration for tons of fun. Features: TempShield double wall vacuum insulation keeps drinks cold up to 24 hours, hot up to 12 Flex Cap is leakproof when closed Honeycomb Insulated Cap for maximum temperature retention