BILLIE JEAN KINGS Eye Coach Replacement Tennis Ball for Tennis Practice Trainer

[REPLACEMENT BALL: Real tennis ball with brass and plastic grommet to use with our Eye Coach trainer. TENNIS PRACTICE EQUIPMENT: See an improvement in on-court tennis skills with only 5 minutes a day. LONG USE: Replace the ball in the tennis ball machine after about 8 hours of use. PORTABLE SELF-TRAINING TENNIS TRAINER: Practice off-court with no distractions anywhere anytime. EYE COACH: Trusted tennis training equipment used by clubs professionals and trainers worldwide.]