FAG Detector III User Manual page 303

Release primary plug
Push the release button (3) down (with a pen for example).
Move the plug backwards.
For use in the USA and Canada
Caution
Attention
Risk of electric shock.
Dry location use only.
This power unit is intended to b e correctly oriented in
vertical or floor mount position.
Pur utilisation a l'interieur seulement.