I just now received this bag and it's great. Bigger than I anticipated, even having read the description and measurements. It has 2 compartments - a big one on top and a smaller, narrow one on the bottom. It's amazingly light and will easily fit anywhere when empty. I am going to give it a workout tomorrow as I am traveling to Nebraska and will use it as a personal carry-on item. On this trip I need to use a max-carry-on sized wheeled bag which has a compartment to hold a laptop and accessories as well as main compartment for other things. Unfortunately the wheeled bag will have to go under the plane as carry-on luggage - the plane is a small regional jet and the overhead bins are too small for this bag to fit. (I am going to miss my Western Flyer greatly!!) My small laptop and a few other in cabin essentials (book, iPhone, snacks, etc) will go in the convertible once I clear security. I let y'all know how it works in this capacity.