Non-contact location of cables with AC voltage.
Checking phase, neutral and earthing conductor at the sockets.
Continuity check, e.g. of fuses, bulbs, etc.
Polarity check, e.g. of batteries.
Display through the LED.
Small and handy.
Because of the super-bright LED, can also be used as a torch.
Inclusive 3 replaceable coin cells.
In blister packaging.