devices for surge protection

one thing I remember, and this was 25-30 years ago, before surge protectors were plentiful, that the article claimed that they only protected hot to neutral or some such and the article put in three MOVs across all three pairs of leads. when I made that I checked it with my cheap three LED electrical tester device and found something reversed. I rechecked my wiring and then plugged mine directly into the wall outlet and all was fine. the 6 outlet strip I had plugged into the wall and plugged my contraption in had reversed H/N. Notified FDA about it, at that time then covered product safety, and was hoping for a big recall but never heard more about it.
bumpy