https://www.eaton.com/us/en-us/products/backup-power-ups-surge-it-power-distribution/surge-protection/how-many-joules-does-my-surge-protector-need-.html
I'm kind of annoyed at this article.
They *sell* [AVR](https://en.wikipedia.org/wiki/Voltage_regulator)s and [SM protectors](https://en.wikipedia.org/wiki/Surge_protector#Series_mode_(SM)_surge_suppressors), they should know better than to oversimplify (and should also be adding links plugging that line of product at the end).
