"Nathan® Pinnacle Soft Flask 18 ounce: The Nathan® Pinnacle Soft Flask 18 ounce is a handheld hydration bottle built for runners who want a lightweight, collapsible way to carry water during training runs, long runs, and trail outings. The ergonomic mesh strap contours to your hand for a secure, comfortable hold without requiring constant grip pressure, so your hand can relax as your effort builds. As you drink, the 3-D collapsible design compresses the flask body, which means less bulk to manage as the run progresses. At 18 ounces (532 mL), it delivers enough capacity for moderate distances without adding unnecessary weight to carry.Nathan’s proprietary ExoSpine™ is a rigid internal structure that creates consistent hand feel and support, so the flask stays manageable even when partially full. The soft flask itself is BPA-free and features a bite valve for on-the-move hydration, and it pulls out of the sleeve easily for refilling and cleaning. A small wrap-around pocket with an elastic opening stores essentials like keys or a gel within easy reach during your run. Weighing just 73g, the Pinnacle Soft Flask 18 ounce is a practical handheld option for runners who prefer carrying hydration in hand rather than in a vest or belt.Why Our Fit Experts Love It""I took the Pinnacle Soft Flask out on a longer weekend run and appreciated how the flask compressed as I drank - by mile eight it barely felt like I was carrying anything. The ExoSpine™ kept it from flopping around, which made a real difference on uneven terrain."" - Sawyer, Road Runner Sports Fit Expert, Wilmette ILWho It's Best ForThe Nathan® Pinnacle Soft Flask 18 ounce is best for runners and athletes who want a lightweight, collapsible handheld hydration option for daily training, long runs, and trail use. It suits anyone who prefers to carry water in hand rather than in a pack or belt, and the wrap-around pocket adds just enough storage for a key or a gel. VIP Family members can take the Pinnacle Soft Flask 18 ounce for a 90-Day test drive with our Perfect Fit Guarantee."