To be honest, I don't know too much about the system other than it is in me ! I'm doing really well after having received my band from Dr. Joseph Moran in Raleigh, NC on April 8, 2009. I have the LAPBAND AP Large. Scheduled for first fill in a couple of weeks but still off to a great start. I don't have much restriction and have only had two instances where I felt "backed up" or stuck a little bit and that was my fault for eating too quickly and not chewing as well as I should have. All in all it is going great !!!