There are a lot of great features to this rolling and expanding pet carrier. For one, the expanding sides allow you to effectively double the \"carrier\" space for your pet in flight. This can ease tension for a more anxious pup, or give you more closeness and access if visibility and proximity are key for you. The extending arm for the rolling base are a nice touch, as I've traveled with my girl in a similar non-wheeled version and I always wished there was an easier way to push her around than trying to maneuver with her weight slung from my shoulder and bonking into everything while i try to also carry luggage. The carrier fits the designated under-seat size for MOST airlines (you'll want to double check before purchase/travel). My new pup is still getting used to it but it's holding up so far and though the wheel base could be a little steadier it's still light years better than not having wheels at all. And especially for the price point (at least, at the time i ordered)