Recommended String Tension: 40-55 lbs. Balance: 34.5cm/(13.6 in.) - Head Heavy Power Level: Low-Medium Stiffness/Flex: 67 RA Frame Technology: Isometric, Oval Pressed Shaft (OPS), Aero Shape Frame Swing Weight: 307 kgcm Swing Speed: Medium-Fast Swing Type: Medium-Full Yonex Ezone Ace ...