They cover for the model numbers: 1171-02 (Sportster 33.6 Voice), 1786, and 1787. Models # 1786 and 1787 are the "X2 technology" drivers.
There are various other drivers included. I suggest using the "Add New Hardware" from the Control Panel for Windows to properly select the right driver for your modem through detection. These drivers are for Windows 95, 98, and Millenium Edition ONLY!
If any of these drivers is'nt working for you and you think they are the correct drivers for it, then that means the modem is bad. U.S. Robotics are known to be a lousy company and I don't recommend them at all. Their modems worked successfully well only with the help from 3Com. 3Com ought to eat up U.S Robotics. Good Luck with these drive