Weight / Grip Size:  4UG5 String tension: 4U:≦ 31lbs (14Kg) Frame Material: High Resilience Modulus Graphite+HARD CORED TECHNOLOGY Shaft Material: High Resilient Modulus Graphite + PYROFIL + 6.8 SHAFT Balance Point: Head Heavy Shaft Flexibility: Stiff *Stringing above the manufacturer's recommended tension can compromise the integrity strength of the racket frame. Therefore, will void the manufacturer's limited warranty.*