These lights work as advertised. Impressive construction as well. I bought 4 BIOMAX 900 lights along with the electric stand. Assembling everything was a lot more work than I expected and the instructions miss a couple of items with the setup I choose. But all in all it was worth the effort. The hard part was over pretty quickly and it's been smooth sailing since. As for effect, it's cumulative and takes time though I feel great after every session. For comfort, I bought a basic massage table which I use for my PEMF mat, sauna blanket, and red lights. Buy and enjoy!