Flip it and sip it.Flip it and sip it with the Hydro Flask 21 oz Standard Mouth Bottle With Flex Straw Cap. With a comfortable flexible handle the closeable leakproof straw cap is easy to open and close with one hand for on-demand hydration. Double-wall insulation keeps drinks cold up to 24 hours for cool refreshment. The slim design fits most cupholders and is dishwasher safe.24 hours cold 12 hours hotTempShield®? double-wall vacuum insulationLeakproof when closedPure taste no flavor transferFits most cupholdersDurable stainless steelBPA-FreeDishwasher safeFlex Straw Cap not intended for use with hot liquidsNot for use on a stove in a microwave or freezer