Trekking Pole Attachment:: The optional trekking quiver is there when you need it and disappears when you don’t. Sternum Strap Adjustor: Two front chest straps provide a snug and comfortable fit. Sternum Strap Adjustor: Two front chest straps provide a snug and comfortable fit. 1.5L Crux Reservoir: Holds plenty of hydration for your longest and toughest runs. Breathable Air Mesh: Keeps you cool and comfortable on even the hottest days.