What is the Highest Power Setting That V-Beam Can Go To? (How Many Joules?)

I have had 2 V-Beam treatments for red marks on my face. The first at 8.75 Joules and the second at 9.25 Joules. Only one red mark ever has purpura, the other either doesn't change or turns redder. The one that has purpura has made alot of improvement and the one that has not has made only slight improvement. For my third treatment, I really want good bruising on both red marks. What is the highest setting that V-Beam can go to (how many Joules) and how many Joules guarantees purpura?