Rain X question

First off I’ve read I guess about everything I could find in here. And a lot are old threads I don’t want to bring back to life. Simple question. And am not interested if it worked or didn’t work as it seems about 50/50. I want to try the rain x on a couple of my cameras. They are the only two that fog or give me problems this time of year at night when rainy or foggy. They both are NOT in ideal locations but my only options for these. I built some overhang covers a couple days ago and helped tremendously. Just wanted to try the rain x to see if that would help with the little prob I have left. Question is. What kind of Rain X?? There’s more than one available. I’m assuming these are plastic lenses ? I would just like to know which one to buy. I’ve seen some of the Ring guys even suggest it. But nowhere have I found which one. Thanks in advance.