This tutorial covers the temperature-sensitive learning sensor, but the same idea applies to the other versions.

Each learning sensor comes with seven sewable holes for you to use:

Power: The hole marked + (plus) is sewn to the + of your battery using conductive thread. The opposite hole is connected to the - (minus) end of the same battery.

Outputs:
    M turns on when the level is "normal".
    H turns on when the level is higher.
    L turns on when the level falls below it.

Calibrate: The hole marked C is attached to a pushbutton switch whose other end is connected to - (minus). Pushing the switch tells the learning sensor roughly what range you want to operate in.

Sense: (custom only)
This hole allows you to connect your own, external sensor. You cannot use this with the light- or temperature-sensitive versions. Take a look at this sample schematic.

Connections (move your mouse over the picture to highlight the wires)