The CamelBak Alpine Explore Hydration Pack has everything you need for a an all-day trip. Its 33L volume stores lunch, energy snacks, extra layers, and your point-and-shoot. The cavernous 100oz wide-mouth reservoir keeps you hydrated for three or more hours. Resilient, high-denier fabric stands up to wear and tear, while properly placed ventilation allows air to flow through and prevent clamminess.