Elenco Sound Activated Switch Soldering Kit with Iron and Solder Hone your DIY soldering techniques on the Sound Activated Switch Soldering Kit Enjoy the pleasure of having assembled and soldered it yourself Just clap your hands together twice and watch the Sound Activated Switch turn on the LED Clap twice more and watch the LED turn off A monostable multivibrator, is a circuit that, once triggered, will switch its output logic level This is the core of the Sound Activated Switch Includes: PCB, electronic components, instruction & 25 watt soldering iron, stand and lead free, rosin core solder PCB measures 639mmX1103mmX16mm Add this kit to your STEM curriculum From the company that brings you Snap Circuits - 9 volt battery not included