Brock String - Vision Convergence Training Tool - Train Vision, Improve Strength & Athletic Performance, and More!

You'll simply love just how easy this Brock String is to use! This Brock String is 6 feet long and comes with 5 beads that fit nicely on the string so you can train convergence at different angles. All you have to do is hold an end against your nose, and try to bring your eyes together at the center of each bead. Click 'Add to Cart' now!