Great kit to be used as a game, or just to get on someone’s nerves. Circuit produces an irritating high pitch for about 8 secs. then shuts down for 2 mins. when it repeats the process. Hours of fun. 9V battery not included.

Principles taught: Transistor, voltage controlled oscillators.

Components: 2 capacitors, 6 resistors, 4 transistors, speaker, slide switch, battery snap