Thanks for your quick answer
Ok now i get it
So the follow combination it could be correct for my board and my weight?
6.7 - 34 sl2 /36 sl4
7.2 - 36 sl2 / 38 sl4
7.8 - 38 sl2 / 40 sl4
I think the sl2 could be better for me because I don’t make only down wind slalom, I need to sail up wind also.
Really Thanks for your help and good job