Double-wall vacuum insulation keeps drinks cold for hours. The insulated water bottle keeps beverages cold for 24 hours. The TempShield insulation keeps drinks cold all day. 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.