Perfect for regular practice and tennis ball machines, the Vollint Coach One are premium quality tennis balls delivering great playability on all court surfaces. They are pressureless to provide consistent performance and long-lasting durability. Plus, these versatile balls have a thick natural rubber core and a woven wool felt to guarantee a longer lifespan and retain their bounce over time. The Coach One are suitable for training, coaching and club play and come in a practical zipped carry bag with an adjustable shoulder strap ensuring comfortable transportation to the courts. They are supplied in a pack of 100 balls.