Garnet SEELEVEL II 709-LL Manual page 8

4. When the programming mode is entered, the display will
show "FrS" if doing the number of senders for the fresh tank
or "GrS" if doing the waste tank. When this occurs release
both buttons.
5. The display will now show "1SE" (one sender) or "2SE" (two
senders), based on what is currently programmed into the
display. These are the only two options, the display will not
work with more than two senders per tank.
6. To change the number of senders, press the tank button, each
time the button is pressed the display will switch to the other
number.
7. When the display shows the correct number of senders, press
the BATT button to exit the programming mode. Each tank
will need to be calibrated individually using this procedure.
The battery voltage is calibrated at the factory, this should never
need to be changed.
Page 8 709-LL Manual