I had to have a little chuckle to myself about this. In the old days, low-level MTBs and hybrid-type bikes came with derailleur protector frames fitted.

Then today in Canadian Tyre, I noticed hanging up on the wall several sizes of the same derailleur protectors (yeah, I know, most self-respecting bicycle tourists wouldn't go into something like Canadian Tyre, but we were looking for a Schwinn floor pump... and we aren't most self-respecting bicycle tourists )

I've often thought of using the derailleur protectors on our touring bikes simply because they travel a lot in cardboard boxes. They certainly add a layer of protection, but maybe I am complacent because our bikes have come through their travels without damaged derailleurs.

They aren't quite as fancy as the one in your picture, but they do come in two difference lengths.