This is an ergonomic keyboard with a built in touch pad mouse. The keyboard is PS2 and the mouse is serial port.
There is very little information about this specific keyboard online. I found a few websites with people discussing the keyboard being rubber dome, and being made / rebranded by a lot of companies such as Quantum Wave, LiteOn Technology, The Wave, SILITEK, etc.
Sources:
Trying to find the company “PC Concepts” turns out to also be difficult. I found a new keyboard company (https://www.concepts.jp/) but I do not believe they are the correct one.
I then found an old Linkedin for “PC Concepts, inc” which may be the correct company, founded in 2000 with 2-10 employees. (https://www.linkedin.com/company/pc-concepts-inc.) but their website is not working, and from what I saw on archive.org (http://www.pcconcepts-inc.com), the website was under construction then became a IT Consulting company… so it may also be the wrong PC Concepts company again.