HYDRATION RUNNING PACK: After rigorous testing & a meticulous pursuit of the 'feeling of nothing on', FITLY has crafted the ideal running hydration vest for trail running & marathons. This lightweight chest pack lets you carry small personal items without being weighed down. Complete with a phone holder, storage pockets & thoracic belt, this running backpack for men and women makes carrying your essentials & maintaining running form ideally compatible. DESIGNED FOR SUB90 RUNS: FITLY has designed 3 separate hydration running vests. The Sub45, Sub90 and Sub180. The Sub45 is designed for shorter runs and does not house the FITLY water bottle flask and tube. The Sub90 running hydration pack is designed for distance runners, featuring 2 accessible stretch front pockets, a phone pocket, a larger pocket & a thermo-pocket with a custom made 500 ml soft flask for hydration on trail runs and marathons. The Sub180 is engineered for the longest distance. FEATHERLESS SENSATION: Designed by runners who understand the importance of feeling weightless and unrestricted. This lightweight hydration vest for running is small and body-fitting, designed with 4 stretch points that move with you. This trail running vest for women and men sticks to your every move for fluid, free movement during marathons, half marathons, races, and training runs without bounce or sway. CUTTING EDGE COMPONENTS: This hydration running vest comes with a clever magnetic closure and silence zipper tabs. It is odor-resistant, moisture wicking, fast drying fabric crafted from recycled coffee ground. The design ensures no item will bounce around. The pockets are water-resistant with 100% anti-sway pack structure. Compatible with hydration bladders and water bottles for hiking, running and outdoor activities. SIZING GUIDELINES: This FITLY running hydration pack comes in two unisex sizes XS-S and M-L-XL and are crafted to accommodate a range of chest measurements. For the perfect fit, measure 2 inches below the pectoral muscles/ band line. If you are borderline between XS-S and M-L-XL, consider thickness variations (jacket, etc) between summer and winter runs. XS/S is 26 in to 31 in (67 cm to 78 cm) & M/L/XL is 31 in to 40 in (78 cm to 102 cm). What makes this hydration running vest different from regular running backpack options? Our water vest for running men women is specifically engineered as a lightweight running vest that eliminates bounce through advanced chest pack architecture, unlike bulky hydration backpack running designs. This running hydration vest features integrated 500ml soft flask with tube system, delivering superior hydration pack backpack functionality while weighing only 0.26kg. The runners vest for women and mens running vest design utilizes body-hugging technology with thoracic belt that traditional running vest options lack. Who needs this running water vest? Athletes training for marathon running vest distances, trail running adventures, half marathon essentials preparation, and ultramarathon challenges require reliable hydration vest for running women and men. This hydration running vest serves runners building running gear for men collections, running gear for women kits, and organizing running essentials men women demand. Ideal for running accessories for men, running accessories for women, and complete marathon essentials. How does the storage system work? Our running chest pack for men women includes dedicated running vest phone holder with water-resistant protection, stretch front pockets, thermo-pocket for flask, and compartments organizing marathon gels for runners, running gu, gel packs for runners, and running snacks. Is this suitable for different activities? This hydration vest works as trail running vest for technical terrain, hiking vest men and hiking vest women trust for outdoor adventures, and versatile running pack for men and running pack women prefer across sports. The unisex running vest accommodates XS-S and M-L-XL sizing with moisture-wicking recycled fabric, rivaling salomon running vest, nathan hydration vest, camelbak running vest, and osprey running vest quality while featuring running reflective gear for night running safety during winter training.