Features & Benefits The new edition of this snug-fitting, body-mapped hydration pack developed in collaboration with elite endurance runner Stephanie Howe now features an Insulated Bladder, for colder water over the long-haul. Includes a 1.6L Insulated hydration bladder, with an hourglass design to reduce sloshing Insulated bladder keep water cooler 38% longer than non-insulated flasks Apparel-like fit with a lightweight, breathable structure Internal compression system tightens the load against your back for stability Zippered water-resistant chest pocket for smartphones Large front stash pockets for quick access to on-the go nutrition and essentials Back kangaroo pocket for stashing flasks, layers, and other essentials Zippered pocket plus two large storage pockets on back Shoulder pill pocket and safety whistle Reflective hits for 360-degree visibility