Vector Ball S is great for Fitness Exercise, Physical Therapy, and Athletic Training. Vector Ball S randomly changes color (Red, Green, or Blue) each time it is bounced, caught, etc. The unpredictable color change tells you what to do next. For example, if Vector Ball S turns Red, catch with Right-Hand, Green, catch with Left-Hand, Blue, catch with Both-Hands. It’s great for fitness exercise, physical therapy, and athletic training (Basketball, Hockey, Pickleball, Baseball, Softball, Football, Lacrosse, Soccer, Volleyball, Tennis, Cricket, Boxing, Mixed Martial Arts, Motor Sports, and more). It facilitates a full spectrum of Cognitive Vision Training exercises/drills, and you take the 3-inch Ball anywhere.