Whadda WSG110 / Velleman MLP111
The Wonky Wire is used to test the steadiness of your hand. It utilizes a circuit with an oscillator that has a very high oscillation frequency of about 3kHz (3000 cycles per second). As you try to trace the outline of the convoluted wire with the loop, the slightest touch will cause a tone to sound. The variable resistor can be used to change the pitch of the tone.