I have a tens massager that has been used and abused and it started giving me problems. I suffer with chronic fibromyalgia which gives me stiffness on joints and muscles and it was time to upgrade and this is it. I dont have to worry about finding an outlet to plug the machine nor running out of batteries. This is USB rechargeable, has multiple settings and intensities, plus is as small as a pack of gum. So i can get the treatment and move arond at the same time.