A high-capacity vest for ultra distances, remote terrain, and the longest days on trail Flow Philosophy Ultra Miles. Unstoppable Movement. For the days when “long” doesn’t even begin to cover it, the Flow 8 is built to keep you moving farther. With 8 liters of storage, it carries the gear required for extended mountain efforts—hydration, layers, fuel, poles, and the essentials needed to push deeper into the mountains. The compression system keeps everything tight and stable, while breathable monomesh keeps airflow high when the hours stack up. When the goal is distance, efficiency becomes everything.