I read reviews for similar products, and many users complained of a swivel feature. It destabilized the rolling/turning process, many said, to the point of having to abandon the darn thing on their trips.

This one is different (and much harder to find): It works exactly like an extension of the handle -- no pivoting. It snaps on/off easily (you probably don't want to check your baggage with it on) and works great.

I'm 5'9", and it greatly improved my comfort in wheeling along my suitcase. Perhaps that is one difference: I have a pullman suitcase (with a handle on the edge), not one of those carry-on wheeled square bags. Perhaps the other type of handle extension works better with those, but judging from other reviews, I'd doubt it.