I've recently been using the Tendlite Photonic Red Light therapy to overcome the EXTREME unrelenting pain of Costochrondritis (a muscle/rib condition caused by chest trauma, like open heart surgery as well hunching over a computer/IPod at home/job or carrying too heavy a backpack). I received the Tendlite Thursday, Dec. 14, (ordered on Tuesday) and immediately used it (arrived with charged batteries) and experienced extremely rapid healing of the chest muscles in like 3 days. Hurrah for Light Therapy. Want to shout out about this device from all rooftops as thousands of people of all ages are suffering from the debilitating pain of Costochrondritis. The pain is like experiencing a heart attack without the heart attack and, therefore, people go to emergency room thinking they are having a heart attack Doctors, of the Dr. Whitecoat variety, are of absolutely no help and often tell patients to just go home and endure the unending pain. Yikes! This is our medical profession here in US? I've made numerous postings on the plethora of Costochrondritis web blogs to alert them of the Tendlite and how quick it will heal the problem. Hope they are listening and believing people. I have used the Tendlite for other additional muscle problems caused by the Costochrondritis and it is helping heal those problems as well. Thank you Lumina Group for this device and for the extemely low price as other very similar devices with same wavelength technology are 5 times this price and, as well, the super rapid delivery to my home. I know that you can use this Red Light therapy on animals as well (including birds) so if either of my dogs are in need of Red Light treatment I won't hesitate to use it for them as well.