These expedition packs have a small 10-liter bag clipped to their fronts. Unlike most other convertible packs, the day bags are actual backpacks with wide, padded straps. This means you’ll not only summit more comfortably, but may also be more likely to use it independently of the larger bag.
Pro: The pack is svelte even with the extra bag attached, measuring only 10 inches deep.
Con: It is heavy for its size, more than 6 pounds for a 55-liter volume, and is most frequently used for extended travel, like backpacking across Europe.
deuter.com; $239-$259