Review on X-ZONE PET Dogs and Cats Carrier: Airline Approved, Soft Sided Collapsible Carrier for Medium Cats, Puppies, and Small Dogs - Perfect for Travel by Darrick Dobbin

I was concerned because Southwest recommended carriers were so small, but I saw another review of this carrier and decided to take a chance. It worked great for my trip. I have a puppy that weighs about 9kg. and stands 10 inches at the shoulders so the dimensions of the stretcher are perfect for this. I will say that the middle and window seats are wider than the aisle seats. So if you want to take advantage of the side opening, which made it REALLY comfortable, plan on sitting in one of these seats. The first picture shows it fits right under the seat (you may have to press the end first to place it then it's ok (11 inches tall). The second picture shows it from above while we were waiting for our flight , it was super comfy as both sides are open so he can really stretch out and watch everything from the safety of carrying.The last picture shows three spots - the walkway under the seat on the left, the middle seat and the Window area.The seat aisle is too narrow to be able to open either side but the trunk will fit with the sides closed it protrudes a few inches under the seat but the flight attendants on neither flight noticed this upon my landing, so they had no problems Carrying this was more than the recommended sizes however a smaller plane could be an issue I would highly recommend this carrier it was perfect and my dog felt great all the time felt good all around.