Hi board,
The spinning leash device will not fit on a "hammerhead" spreader hook. So all you need to do is change the spreader bar to a standard hook if you have the Hammerhead and it will fit onto any harness.
The system works pretty well and allows you to unspin the safety leash pretty easily. Airborne Kitesurfing will have them in stock in Ozzy Park.
Good winds,
