Attitude Supply ATD2 Backpack vs. Six Moon Design All Day Carry Travel Backpack

Two carry-on travel backpacks, compared spec for spec.

Attitude Supply ATD2 Backpack

Front facing view of the Attitude Supply ATD2 Backpack
Capacity18 L
Weight1.3 kg
Dimensions45×25×19 cm
Airline fit96%
Price$475

Feature by feature

Attitude Supply ATD2 BackpackFeatureSix Moon Design All Day Carry Travel Backpack
Storage
4 Compression 4
31L Expanded Capacity None
1 Opening 1
front Passport front
Y Passthrough Y
Carry
removable Backpack hideable
removable Hip Belt removable
removable Sternum Strap removable
Inside
15in Laptop 15in
2 Main Compartments 4
Y Organizer Y
Outside
× Hard Shell ×
N Rain-fly N
2, side Water Bottle Holder 2, side
Y Water Resistant Y
Material
Challenge Sailcloth Ecopak® EPLX600Robic Nylon (100D and 200D Challenge Sailcloth EPX200 Challenge Sailcloth ULTRA

Six Moon Design All Day Carry Travel Backpack

Front facing view of the Six Moon Design All Day Carry Travel Backpack
Capacity35 L
Weight1.3 kg
Dimensions55×30×18 cm
Airline fit86%
Price$335

Key differences between the Attitude Supply ATD2 Backpack and Six Moon Design All Day Carry Travel Backpack

Both have: compression straps, passport pocket, luggage passthrough, hip belt, sternum strap, laptop sleeve, built-in organizer, water bottle pockets, water resistant.

Which airlines take each bag as a carry-on

We checked both bags against the carry-on size limits of 189 airlines. 163 accept both. 18 accept only the Attitude Supply ATD2 Backpack, and 0 accept only the Six Moon Design All Day Carry Travel Backpack.

Only the Attitude Supply ATD2 Backpack fits

Air Niugini, Air Tahiti, American Eagle, Belavia, easyJet, Etihad Airways, Great Lakes Airlines, Gulf Air, Liat Airlines, Oman Air, Qatar Airways, Ravn Alaska, Regional Express, Royal Jordanian, Scoot, Tiger Airways, Virgin Australia, WestJet.

Attitude Supply ATD2 Backpack vs. Six Moon Design All Day Carry Travel Backpack: which should you pack?

The Six Moon Design All Day Carry Travel Backpack carries 17L more than the Attitude Supply ATD2 Backpack (18L vs. 35L), while the Attitude Supply ATD2 Backpack is the lighter pack at 1.3kg (vs. 1.3kg). For carry-on flexibility, the Attitude Supply ATD2 Backpack fits 96% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Six Moon Design All Day Carry Travel Backpack; if you want to travel lighter, the Attitude Supply ATD2 Backpack is the better call.