Firmware 4.1 or 3.1

Trying to remember what firmware version my dongle has to flash. It was recently purchased.

Update: Found the answer in the Getting Started document. Its printed on the board.

The board shows the hardware version - 2.1 is the Bluetooth Classic, 3.1 is the Bluetooth Low Energy (BLE) version, and 4.1 is the new BLE board not yet in production. The 3.1 board can be upgraded to 4.1 by sending it in for the upgrade but it will still how 3.1 on the board.

What is the address to send the adapter for upgrade?

It's on the order page.