Windwing are the second manufacturer to include a "zipper" system on their kites.
The object of this zipper is to change the trailing edge (leach) tension and therefore, the power and handling charecteristics of the kite. Kind of like 2 in 1.
RRD who are the other company to have used this system, have as many as three or four zippers on some models. I guess time will tell whether this is the way of the future. The pics are courtesy of Rick Iossi and FKA
