I had physical therapy for a back problem. They offered a lazer light treatment @ $35 per 15 minute treatment. I went on line and found this light. I was skeptical but, since offered money back guarantee, I gave it a try. Well I am an older guy and have some pains in my hands as well in the lower back. I use the light when I have aches and pains. It really works for me! I don't understand it but I'm keeping it.