TP-LINK MC220L 1000M RJ45 to 1000M SFP Slot Supporting MiniGBIC Modules

I have 2 of these that I use to isolate my network from the power grid. After having suffered several power surges and close lightning strikes, these are cheap insurance. They work flawlessly. Lightning is far more likely to come in on you cable than on the power line. It's usually the network interfaces in computers and network switches and your router that will be destroyed. Using these, a couple of optical transceivers and a fiber patch cable will electrically isolate your stuff from the cable. Except for your cable modem, it has to be plugged into the cable and thus is vulnerable. But I'd rather replace just the modem than it and a bunch of other stuff.