Training and exercise ball is made from high-quality, Italian resin to resist bursting during your exercises. Flexible construction is soft and lightweight for comfortable handling. Strong, durable design keeps the air pressure at a consistent level to prevent frequent adjustments. Training/exercise ball is perfect for improving balance, posture, flexibility, core strength and hard-to-reach muscles.Training and exercise ball is made from high-quality, Italian resin to resist bursting during your exercises. Flexible construction is soft and lightweight for comfortable handling. Strong, durable design keeps the air pressure at a consistent level to prevent frequent adjustments. Training/exercise ball is perfect for improving balance, posture, flexibility, core strength and hard-to-reach muscles.