What is the trigger for?
The trigger is found below the case. It allows you to discriminate(reject) iron trash only when you pull the trigger. The lock/unlock switch on the front panel allows you to lock or unlock the trigger. If you lock the switch, the trigger will be locked or it will discriminate all iron trash automatically. If it is unlocked, the detector will only reject iron when the trigger is pulled.
Other Help Topics
Here are some more help topics on the detector: