TONK is a Russian Company with a range of thin clients. I know nothing about them and doubt I'll encounter one in the flesh. However shortly after I added the Centerm C92 to the site I heard from Igor and thought it worth including his comments about Tonk/Centerm on the site.
In the Russian Market many products branded as TONK are actually Centerm OEM. For example TONK 1200 series/Depo "Sky M53" is Centerm F2950 with pretty standard AWARD BIOS.
Google and the wayback machine will find you plenty of information on current and past products.
Igor also provided a link to a page that included details on the F2950 mentioned above.