These are a copy of Maxim's DS9490R 1-Wire host adapter.
I've bought these to stock as the genuine ones are impossible to find at a sensible price at the present time.
They're based on a microcontroller and appear to your host machine exactly the same as a DS9490R. I've tested them with OWFS and they work perfectly. They have a DS2401 ID chip on board.
I'm selling this first batch of ten at near enough cost price and would very much welcome feedback from those who purchase them to determine if I continue to stock them.