I just read about a new wheeled carry on bag that claims to be the lightest in the world. (Questionable.)
The July Carry On Light is from an Australian company but is available in the US.)
The specs:
Weight: 1.8 kg/3.9 lbs
Volume: 32L
External Measurments: 54 x 36 x 19 cm/21.25 x 14.17 x 7.5 in.
Internal Measurments: 46.5 x 35.5 x 19 cm/18.31 x 13.98 x 7.5 in
(Specs came from their website.)
It comes in a few different colors. The cost is $245. (Not cheap.)
There is an expanded version that weighs one pound more and the depth starts at 8.6 inches and expands about an inch. Volume goes from 35 L to 40 L) It costs $20 more.
I have not seen this bag in person so I can't say if it's good, bad or somewhere in between. But I know some here are always on the lookout for new bags.