This is LED / PDT Red Light Therapy Cold Laser Pain Relief Heals Body Tissue... This infra-red light tissue healer is used but in great condition... I believe it just plugs in...I did not use it I'm not sure if the whole light thing is 100% true... I'm not a doctor but I know other people say these work great... Please look at the pictures and if you have any questions or if you want more pictures feel free to ask..