Bob’s Quick Take: This Osprey Ultralight Collapsible Stuff Pack is a compact 18-liter daypack made for travelers, campground wanderers, and families who want an extra bag without giving up much luggage space. It is best for light day use - snacks, water bottles, rain jackets, souvenirs, and short hikes - not for heavy loads or rugged backcountry hauling. The big win is packability; the main caution is that the very lightweight design means limited structure and organization.