There's a new fifth line system on the block, and it looks like a tidy little unit, too. It can be connected at the leash end to either Slinghshot's Surefire Bar or the Surefire Pro.
Slingshot was featured in Issue #14.
Kitesurfing Test - Boards 2013
Kitesurfing Test - Kites 2013
Airush Lithium Zero 18m
Kitesurfing travel directory