THE BEST BOTTLE: A 24 oz Wide Mouth water bottle with Hydro Flask's leakproof Flex Straw Cap—easy to fill, easy to drink. Open it up, add your ice, and flip to sip. The insulated stainless steel keeps it cold for up to 24 hours. 24 HOURS COLD: Double-wall vacuum insulation keeps drinks hot or cold for hours. The insulated water bottle keeps beverages cold for 24 hours. The TempShield insulation keeps drinks cold all day. LEAKPROOF: Say goodbye to leaky water bottles. The Flex Straw Cap is leakproof when closed. Simply close it shut and toss it into your bag without worry. Sip effortlessly with one hand, thanks to the easy-to-use straw design. Click it shut, and rest easy knowing your drink stays securely sealed all day. FITS CUPHOLDERS: The cupholder-friendly design means your bottle fits seamlessly in most cupholders. Designed for seamless cupholder cohabitation, it's right at home on the open road, on the sidelines, in a pack or wherever you need to