A adjustable spacer mod for fine tuning your skewer/Harpoon to make minor FPS adjustments.
Includes a part that can lock in place with screws for tournament FPS locking.

Directions:
1. Thread screw into spring cup and work in the threads a bit before further assembly.

2. Line up the tabs and insert the screw and spring cup inside the backcap.

3Assemble like regular skewer replacing the backcap and B-knut with the new ones provided.