Yes, the article is technical. I use the abstracts as evidence of what I say - one can't deny hard science! :)
The item I use has 660nm Red Light & 850nm Infrared Light. The 660nm is for the skin surface, and the 850nm penetrates deep down.
I ordered my body size panel from Alibaba and it cost €200 plus €100 for transport. You can, however, buy various models on Amazon.
This is similar to what I have.
What I gather from the research I read is that NRL and red light increase the energy in the energy cells (mitochondria) and that it is the slowing down of the mitochondria that causes disease.
Good luck.
PS I found some more ones that were similar to what I bought.
If you look at this one, you will note that it doesn't give the nm measurement. So before you buy anything, look at the nm measurement. Also spend time reading up about it.
