Just about any UPS will work. You do need the 12v adapter that Neptune sells to plug into the UPS, and then to the APEX (Unless they're included these nowdays--I don't know. The adapter wasn't included when I bought my apex about 2 years ago. I think I paid $12 or so for it from Neptune). As PilotWolf mentioned, you need to also have another UPS for your Cable/DSL Modem, as well as your router. You can either use the same one, if your modem/router is near your Apex, or you can just buy two UPS's. I'm using a few APC ES-550 that I bought at Fry's a few years back for around $40 each.