Excerpt: While I can't comment on its ability to prevent damage due to a power surge (haven't had that yet), it did work fine when hubby turned off the power at the circuit box. What I was surprised to find was a light that tells you the circuit is properly wired so the unit can work properly.
Summary: Just want to warn others that the image of this surge supressor is not correct. The model that ships is a newer configuration, you can see images on Amazon or other sites. It has the same number of outlets and connectors though.