How to use: You can easily attach tools to a metal workbench by simply placing these magnets on the tool and the workbench. If you want to use them for kids on the fridge, just let kids hold them and stick to the fridge. For reed switches, keep them within about 3cm to activate the switch. Note: Keep these magnets away from electronic devices as their strong magnetic field may damage them. Also, don't let small children swallow them. Maintenance: Wipe them with a dry cloth to keep them clean. Store them in a dry place to prevent rusting.