I have been having knee pain for severalweeks and nothing seemed to help.I haveused this infrared device on the first settingwith all 3 light types for 5 days.l only usedionce per day for the recommended 3
minutes.It shuts off automatically after thatMy knee pain definitely seems less.I willupdate again if the pain gets better orworse. The device itself is easy to use andthe instructions are very clear and helpful