The Aeronaut is all of the above. It takes the best of all of those bags and combines them into what may be the most versatile travel bag yet.

A maximum carry-on size bag, the Aeronaut converts to be carried as a backpack with zip-away backpack straps that were designed by Tom to be comfortable for people of all sizes. (See this user review of the Aeronaut for pictures of the bag being worn by two people of different heights (5'2" and 6'0").

A padded handle allows it to be carried on-edge as a one would an old-fashioned suitcase, and double-coated steel "D"-rings accept our Absolute so you can carry it on your shoulder as well (almost anyone else's shoulder strap will work too).

The down-side to most duffel bags is their lack of compartmentalization: we think we've answered that quite successfully with the Aeronaut. The main body of the bag is divided into thirds. A large center compartment is flanked on both ends by substantial end pockets; these end pockets can easily accommodate size 12 running shoes: now maybe you can take all the shoes you need with you. The end pockets also are great for segregating the clean from the un-clean, or perhaps socks and underwear, from everything else.

The main compartment is accessed through a curved zipper opening and swallows a substantial stack of folded shirts/blouses/trousers/dresses; as you pack the Aeronaut, the end pockets act like bookends, keeping everything in the center compartment relatively flat and folded. The inside of the opening "hatch" features a convenient zippered mesh pocket to contain small items. Packing Cubes, sized specifically to most efficiently utilize space inside of the Aeronaut, are available for order here. We also offer convertible Shoulder Bag and Backpack Packing Cubes sized specifically for the Aeronaut: use them as Packing Cubes inside of the Aeronaut and once you reach your destination, unpack them to use them a a lightweight shoulder bag or backpack as you explore. One exterior zippered pocket has a key snap and is large enough for Le Guide Michelin or plane tickets (keep an eye on those tickets and passports -- it may be best to keep them on your person).

The Aeronaut converts to and carries comfortably as a backpack: padded, contoured shoulder straps feature a removable/adjustable sternum strap, and the back panel is padded with closed-cell foam as well. Of course, because it is carry-on size, you usually won't be checking it as luggage.

If you do, the backpack straps easily tuck away inside and the Aeronaut becomes a sleek and stylish soft-luggage piece, free of extraneous straps and gee-gaws and entirely presentable. Padded grab handles on either end make pulling the Aeronaut from an overhead storage bin or from under your seat a cinch. Travel with the Aeronaut isn't like travel with wheeled luggage: you won't ever hesitate to make your way through the crowd, down a cobblestone alley and across the grass. With the load on your back, you can navigate through not just airports, trains stations and bus depots, but through airplanes, trains and buses.

The Aeronaut is made of heavy-duty 1050 Ballistic nylon with splash-proof YKK #10 Coil zippers, and is built to withstand years of worry-free abuse.