The Black Diamond Distance 4 Hydratation Vest is a trail running backpack designed for long distance races and fast paced adventures, this gillet features a pocket made of comfortable stretch material that extends from the hips to the back panel with self-fastening stretch mesh edging for maximum comfort on the move. The Z-shaped carrying system can be easily used on the move. The harness design also offers quick-access side pockets. The double water bottle pockets accommodate two BD HydraPak® SoftFlasks™, which are included in the waistcoat. BD Black Diamond Distance 4 Hydration trail running backpack