Only the most popular modems are included in the FirstClass Client archives with release 3.11. If your modem is not in there you can download the self-extracting archive Other Modems.sea. This will give you over 500 more modems to try. There are ALL updated through FEB 96. Be sure to copy the modems files you want into the folder named MODEMS on the same level as your FirstClass Client.
These are the modems included with the 3.11 Release of FirstClass Client