Seems to work flawlessly, for a lot less money than buying new. Of course, you never really know about safety equipment until you need it. So if you're a "belt and suspenders" type, you might want to buy a new one. But I'm happy with my purchase.
The possible problem with purchasing used Surge Protectors is that when a surge protector is new, all is wonderful. However, with each and every "HIT" the surge protector absorbs, the silistors inside the unit begins to "weaken". Depending on how many of the "hits" the protector gets in its lifetime, it's efficiency tends to degrade. So just keep this in mind when purchasing any used electronic device. The Silistors are not expensive, & really should probably be replaced before you install the used surge protector in your application. I have not done so at this point, and I therefore should be "Shot at Sunrise". I'm just always behind in my work, so I have taken the risk so far.