Just clip it over the wire sheathing
Photographs for construction reports can be taken by lighting the arrow lamp (in case of positive phase)
The rotating LED display allows you to see the phase order of the three-phase power supply at a glance.
Notifies you with an intermittent beep when the phase is positive, and a continuous beep when the phase is out of phase.
Comes with a magnet so it can be fixed to the switchboard