Monoprice 6-Outlet 500W Rotating Wall Tap Surge Protector (Black) EXPIRED

No UL listing.

You want a surge protector with a clamping voltage of 400V or less. The one in OP is rated at 500V. The lower the clamping voltage the better, with the best outlet surge protectors rated for 330V clamping. Monoprice sells a few rated for 330V and UL listed for just a few bucks more. The clamping voltage is the voltage that it will let through before it trips. If you live in the US, your outlets are 120V. 500V is a lot more voltage than your appliances are designed for. At that voltage, a surge is doing damage to your appliance, whether it kills it instantly or not. The Joules rating is the amount of energy the protector can absorb before it fails and no longer offers protection, and is cumulative. They eventually fail after they've absorbed close the rated Joules of surges over the life of the protector. A whole home surge protector is the best option, and are relatively cheap ($90 for a type 2 Eaton), but should be installed by an electrician if you don't have the requisite electrical experience, as making a mistake in your breaker box could kill you. If you don't know someone with electrical knowledge that could help you out, an electrician's labor cost would be around $100-$200. That's quite a bit more than an outlet surge protector, but would offer much more protection for your whole home, and would be a much better investment if you own your home. I know this is much more information than you asked for. Just spreading the word on the misleading marketing tactics of many of these manufacturers, and the other options for those who read this. Using these cheap, low protection surge protectors could be much more expensive in the long run.

if you are right - this needs to be higher. one of the questions asked/answered at MP says it is UL listed.

are you saying that because the pictures don't show it? or because you own or owned one? Thanks