The following is the latest firmware for each scale:
To check your firmware:
With your scale powered off, press and hold the power button. When "SEt" displays, release the power button and the number that flashes after is your firmware version.
[For Lunar firmware 2.6.003] With your scale powered off, press and hold the power button. Short tap the T button and you'll see the number flash for the firmware version.
Here is an example of checking the Lunar's firmware:
Previous Lunar firmware:
Previous Pearl firmware: