Bought this in May 2015 to treat carpal tunnel pain in my right hand...it worked and I quit using it the since pain was gone...developed type 2 diabetes in 2017...begin to experience diabetic nerve pain in my left foot in bed at night, it wakes me and is very painful. About 3 weeks ago I remembered my red light and tried it...Amazing that within 1 minute after shining the light on my foot the pain goes away. Even more amazing the device still works after 3 years of not using and the batteries are still good and recharge like new.