Considering the back? Neck and in the center of the shoulders. I have now several sessions (8-9) completed and i can see some resuslts on my upper arms and my lower back which is working fine. On the spot between my shoulder (lower neck) and the shoulders itself it´s still no progress. My studio is using a J/cm 10.0 & a KJ 8.00 setting and a very fast beeping. Iam slightly tanned and i have black hairs. Can you give a working range or it´s more a question of the duration of pulsing Nanosecs?