My 55 + 10 Backpack fit exactly into it fully loaded (Size: S). I have completed 15 flights with the cover. At the airport the backpack in and then two more packing bands around it and even the backpack was well protected. Thanks to the handle sheath like a Duffle Bag is portable, which is why I have the backpack partly already on the bus and on the way to the airport to then take the last few meters as a bag. At the end of the trip they had a few small holes. Since the baggage are just exposed to about flying a heavy load, that was probably inevitable and I will now discard. On the other hand one can not expect more from a light shell and the holes are not torn. Better the shell gets everything from when the backpack itself. It fits very relaxed way, in a typical lateral outer pocket of a large backpack and filled it about halfway, at least on my Deuter.
