It's a cable and it works. The cable plugs in and fits just like the cable which came with my Starlink dish. It arrived in Starlink packaging. As far as I can tell, it's an authentic Starlink cable.
The original cable works just fine, but I needed another cable so that I could use my Starlink dish at home without removing the original cable from my RV. The original cable is ran through my RV roof and I would have to reseal the entry hole if I removed the cable. I've been in a Starlink feedback program for years and I could lose my program benefits if I don't use at least 20GB of data per month (the program is only available to SpaceX employees). What more can I say?