The Patagonia Black Hole 5L Waist Pack is built from 300-denier post-consumer recycled polyester ripstop with a TPU laminate that keeps the shell structured and weather-resistant, backed by a 200-denier recycled polyester lining with PU coating. The result is a pack that carries the essentials on a trail loop or a long day in town without adding bulk to the load. What Our Gearhead(R) Experts Are Saying:"The 5 liters sits right at the sweet spot for a half-day out: enough for a water bottle on each hip, keys, a snack, and a light layer, without the pack ever feeling like it's there."