Wilson Triniti 4 pcs tennis balls wrt115200 Wilson tennis balls are responsible for improving performance during competition games court. Pressure balls are exceptionally durable. The structure of felt is 50% more flexible compared to traditional felt for tennis balls, which translates into better feel of the ball. Core Engage containing plastomer material significantly extends the life of the ball while keeping the parameter in.  In paper, the recyclable octagonal pack contains 4 balls.