Cotopaxi Allpa 28L Travel Backpack - Lightweight Durable Carry-On Pack for Hiking, Camping & Air Travel - Water-Resistant Daypack with Laptop Sleeve (Fatigue Color, 28 Liter)

I travel a lot, from airplanes, to cruise ships, automobile, and train. The demands on the right travel packs is important, and the size and durability are top on the must need for me.I chose the 28L Allpa mainly because I have used other 40L, 50L and 60L packs, and the right weight and comfort seem to land me at 28L. I do marry this pack with the Cotopaxi 38L roller for my complete travel plans because I normally have between 35-60L of stuff I pack for a 1-2 week vacation.The 28L is a great 1-2 day bag. It can hold for me 3 pair of socks and underwear, 3 shirts, 2 pants, 1 pair of shoes, shaving kit, tech bag and 13" laptop. Depending on the season, you may be able to pack more. When fully packed the Allpa sits comfortably on the back, and it has adjustment straps and a hip strap if needed to more adjustable comfort. The clam shell opening is great for access, and the mesh netting provides a bit more stability when packing and closing. The outer construction is a nice weather resistant material, and the side mesh water bottle pocket is a nice touch. There are handles on the top and bottom, and one on the side opposite of the bottle holder, which makes it ease to lift in and out of over heads, trunks, or under seats. The 28L Allpa can fit under a seat for plane travel, even fully packed. There are a total of 4 different compartments (zipper) that can be used, one small one in front for money, wallet, cellphone charging cable, a 1/4 zip pocket that can hold toiletry bag, keys, small items, the main compartment with has a full mesh zipper side and another side that is 3/4 size for shoes and other compactable items. The back has a velvet pocket that can fit up to a 15inch laptop, and an additional sleeve for a tablet of portable screen. All the zippers are color coded so you can know what compartment you are opening, and they are YKK durable.You can get the Allpa in a larger size, but I found this size manageable for me and my needs.