the device is labelled as manufacture by either keyfax or g.media.
well out of production, the specs are still available on the original site and also backed up on the wayback machine.
specs
http://keyfax.com/keyfax/phatboy/phatspecs.html
https://web.archive.org/web/20210210210819/http://www.keyfax.com/keyfax/phatboy/phatspecs.html
tips
http://keyfax.com/keyfax/phatboy/phatips.html
https://web.archive.org/web/20200220204210/http://www.keyfax.com/keyfax/phatboy/phatips.html
compatibility
http://keyfax.com/keyfax/phatboy/phatcompat.html
https://web.archive.org/web/20210211051522/http://www.keyfax.com/keyfax/phatboy/phatcompat.html
pictures of v1
https://www.matrixsynth.com/2015/12/keyfax-phat-boy-midi-hardware.html?spref=pi
