FWIW, talking to a mfg rep, the 'WR' designation refers to the 'plastic' that the device is made from. I don't know the tech features or descriptions, but the 'plastic' is supposed to be basically UV resistant.
Keep in mind I'm not a chemist,only a sparky & inspector, and this is what I was told.
The GFI protected, TR-WR receptacle living within the 'bubble cover'; how much more can we protect it.
