Based on driver databases, hardware forums, and USB ID repositories, PID 198A specifically points to a USB-to-Serial Bridge Controller or a Data Acquisition Module.
In practical terms, this ID is commonly found in: usb device id vid 1e3d pid 198a top
Crucially: This device is not a standard USB flash drive. If Windows asks to format it, do not format it. You will destroy the firmware. Advantages of Silead 198a : Cost-effective for OEMs
If you plug this device into a Windows, Mac, or Linux computer, you might notice it initially appears as a CD-ROM drive or a storage device rather than a modem. Based on driver databases, hardware forums, and USB
This is the top trick for stubborn PID 198A devices.
If you are on Windows 10/11 and trying to install a driver from 2015, Windows will block it.