4m building set stress tester

Build your own electric buzzer circuit with this stress tester building set from 4M. Can you handle the stress as you guide the handle from one side of the circuit to the other? Don't touch the wire, or the buzzer will sound!

It's a fun, playful way to learn more about how electricity works. Use the bendable metal wire to shape different circuits and challenge yourself and others even more.

The building set includes everything you need to build the stress tester, including detailed instructions in various languages and a small motor; only the batteries (AA 1.5 Volt) are not included.

4M indicates that this set is intended for educational purposes. We therefore recommend doing this project with an adult or someone over the age of 12.

This is item 9191163 in Het Mooiste Speelgoedboek 2026 from ilovespeelgoed.nl.