Here you can find some detailed shots of the batten tuning of an ARX 15.5.
The result is good, makes the kite turn faster. Don't expect too much, but it is definitely faster
Price: approx. Euro 50, if it is done by a professional seamer.
This was done by http://www.sailloft.de
in Hamburg, Germany
Here you can see how the batten is sewed at the inside and tip of the kite. Since the batten is under tension, the kite doesn't flutter:
This is the frontside of the kite where a small bag holds the batten and protects it from moving:
At the backside the batten goes through a little bag and then you can put tension on the batten while closing it with double velcro:
To get better quality, since the material is quiet thin, here the outside of the kite:
Closer shot of the reinforcement at the outside of the kite: