The smartest and most functional designs are often the simplest and the Piorama Adjustable Bag, that riffs on the classic duffel, epitomizes that philosophy. Three different sized bags–31L, 46.5L and 62L–in one, with three ways to carry–backpack straps, handles, or shoulder straps–it also packs down to the size of a football. Forged from technical nylon for strength and weather resistant, the main compartment is lockable, too.