Hydration on the go just got easier with the leakproof, insulated Flex Straw Cap. Add it to your favorite Standard Mouth Hydro Flask bottle to easily enjoy cold hydration anywhere.
Stainless steel, cup holder compatible, fits right in your pack—our 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.