Manual calls this card the "Mwave Chameleon Multi Function Adaptor". Came boxed as the "Rhombus Chameleon". Drivers work fine in the UK with Windows 98SE, but should work with lower OS.
These Drivers are the latest I could find for the card which appears to be a rebadged IBM Windsurfer.
Note that you have to "launch" the modem first to initialise it before using it, an icon will appear in the system tray.