I had come across the amicikart voltage cutout protector a couple of years ago but I ignored it and passed it off as a mass produced gimmick. In the meantime my led tv hdmi ports got fried on two occasions thanks to Adani's overvoltage surges and hence the motherboard had to be replaced twice which was irksome to say the least! Heaven then sent advice the second time in the form of
@mbhangui which I didn't ignore. Instead of the entire home, I've got three of these cutout protectors protecting three specific fragile zones i.e. the refrigerator, ledtv/hifi line and pc.
Check this out -
What I find praiseworthy about this device is the ability to fine-tune over/under voltage and over current cutoff values to my preference instead of a fixed range on other devices which cannot be tweaked.