I have a spinal cord stimulator implant from Advanded Bionics. I had it implanted in December 2007. It has a round diameter and is just below my rib cage with the electrodes implanted in my neck. It is very comfortable. Also, the device from Advanced Bionics like I have has an internal battery life of about twenty-five years. The devices from Medtronics have been shown not to last as long. My spinal cord stimulator (also called a neurostimulator) has enabled me to quit taking two of my pain meds since I had it implanted in December 2007. I have more energy and have lost some weight. My doctors, one of who is the best in the world, relies on the Advanced Bionics brand and model of spinal cord stimulators. Good Luck.