For some reason I have not had any luck with posting images or links in this site.
But I think I figured out this 7443 bulb. Since the lens assembly is all plasic, there is no sheet metal ground for the traditional bulb metal base.
So two contacts are ground by wire and the other two are for brake and tail lights. And the socket is designed so that the bulb can just be pushed in without thought to orientation.
There is a caution on the packaging that warns against leaving finger prints on the bulb’s glass envelope, so I think it is a halogen.
It all had added up to a working brake light. This car has 260 000 kilometers, and this is the first bulb to burn out. Pretty amazing. But not LED life either.