Both existed, and in many cases it wasn’t exactly clear which was which. Moreover, surge protectors used sacrificial components that would not age well, and th

Both existed, and in many cases it wasn’t exactly clear which was which. Moreover, surge protectors used sacrificial components that would not age well, and they would stop being effective at their job. But you’d look at the LED and it would still be green, so you’d think you were safe. And most people didn’t know that you weren’t supposed to plug a surge protector into another surge protector. There was much confusion, and to a degree there still is.