In North America, the standard unit of measurement is %BAC. If you need to change the unit of measurement please follow the steps below:
Begin by pressing Start and then holding down "mode" for 5 seconds while the device is counting down. This will prompt the device to cycle through the different modes it is equipped with.
The first mode the device will enter is "Unit".
Press start while the OLED screen is displaying "Unit" to cycle through the different units of measurement and stop on the unit of measurement you need.
Below are examples of what the setting screen will show when you are changing the units of measurement:
