1a61:3950 — FreeStyle Libre 2

This is the USB identifier for a FreeStyle Libre 2 manufactured by Abbott Diabetes Care. The vendor ID 1a61 is registered to Abbott Diabetes Care with the USB Implementers Forum, and 3950 is the product ID that Abbott Diabetes Care assigned to this particular model. When you run lsusb on Linux, this device appears as 1a61:3950 Abbott Diabetes Care FreeStyle Libre 2.

Linux

$ lsusb
Bus 001 Device 004: ID 1a61:3950 Abbott Diabetes Care FreeStyle Libre 2

You can filter directly with lsusb -d 1a61:3950, or get the full descriptor dump with lsusb -v -d 1a61:3950. Kernel messages from dmesg show the same pair as idVendor=1a61, idProduct=3950.

Windows

In Device Manager, open the device, go to Details → Hardware Ids. This device reports:

USB\VID_1A61&PID_3950
USB\VID_1A61&PID_3950&REV_0100

From PowerShell: Get-PnpDevice | Where-Object InstanceId -match "VID_1A61&PID_3950"

macOS

$ system_profiler SPUSBDataType
    FreeStyle Libre 2:
      Product ID: 0x3950
      Vendor ID: 0x1a61  (Abbott Diabetes Care)

Having driver issues with this device? Most USB devices are handled by a generic class driver; if yours shows up as an unknown device, confirm the ID above first, then check the manufacturer's downloads page.

The exact lines this page is generated from, in the upstream source file:

1a61  Abbott Diabetes Care
	3950  FreeStyle Libre 2

• 1a61:3410 CoPilot System Cable
• 1a61:3650 FreeStyle Libre
• 1a61:3850 FreeStyle Optium/Precision Neo

See all 4 devices from Abbott Diabetes Care →