I did as much research into UPS units as I thought I needed in order to understand all of the top level jargon, but the fundamental issue of whether the appliances plugged in will be physically protected hangs over the entire industry (for domestic use). For example, a CyberPower UPS unit claims that it employs "Surge Protection & Filtering" with a surge "suppression" of 405 Joules. However, lighting will strike power lines with many hundreds of thousands of Joules, so how can such a UPS be of any genuine use? ref: https://www.cyberpower.com/uk/en/product/sku/CP1500EPFCLCD My reckoning was that the lightning strike would be sufficiently suppressed at the power station level before it reached my home's power lines, but I just don't know, there are many variables. Just how realistic can domestic computing hardware be protected when plugged into utility supply? (through a UPS) Another thing: there is apparently no such thing as a perfect sinusoidal wave, both "clean" and "dirty" power suffer from spikes; noise, and ripple voltages, but with the way DC powered microelectronic devices are designed today they do not suffer from these fluctuations as UPS manufacturers would have us believe, such claims are then a gimmick? The one thing I need are solid numbers, not claims, but the actual irrefutable numbers. I am not smart enough to do that, I need help from people that are, to put this issue to rest. Thanks.