Osprey's Skarab 18 Hydration Pack combines a minimalist design, with ample support and storage to keep you ready for wahtever your hike has in store. A foam framesheet with center stiffener makes the Skarab capable of comfortable carrying up to twenty-five pounds and the included 2. 5-liter hydration reservoir is typically capable of carrying all the water we need for a full day in the mountains.