About this item High quality: These reflective balls are made of durable high-density rubber and feature a six-hemisphere design that provides a dynamic and optimal bounce. Suitable for use on all hard surfaces. Improve reflexes: Helps build reaction speed, motor sensory skills, and peripheral vision tracking ability. Enhances coordination and reflexes. Can also be used as a rehabilitation and exercise tool. Instant feedback: Reaction balls are designed to bounce unpredictably, providing immediate feedback on reaction time. This helps improve hand-eye coordination and response speed. Multi-purpose: Excellent training tool for various sports including baseball, football, soccer, tennis, kickboxing, and basketball. Training anywhere: Compact design allows for training anytime, anywhere. Helps improve agility and speed. Ball diameter is 2.75 inches (7 cm).