Battery powered of course.
And it will weigh 10 pounds.................
Watch....solar powered...set in on your windowsill..or car dash...
Yes but the calls will come from inside your house!
---------
Actually this makes some sense. Given his capital and the ease of contracting a phone (google does it) it's probably all about the software - and in this case, he may try to integrate it into his vision for Twitter becoming "X - the everything app" - text, voice, payments, media player, and government 'social credit score'... And you can call your tesla on it and connect via starlink and book a reservation on one of his rockets.