The O3 Speedport Black provides advanced level players more feel in an aerodynamic mid-wide frame. Players may choose the String Port Insert for a softer feel with improved string damping. A firmer feel may be chosen with an increased string feedback by choosing the String Hole Insert. Specifications: Headsize: 100" Strung Weight: 11.3 oz. Length: 27" String Pattern: 16X19 Strung Balance: 5 points HL Beam Width: 23-22-22 mm Tapered Beam String Tension: 53-63 lbs. Product Reviews: "I recently purchased this and loved it. Incredible power and control on both sides. Not as much pop on the serve as my old Diablo. Use the String Ports. Recently lost some control of soft shots and power strokes. Don't know if it is related to older string causing a decrease in tension. Would like to get some feed back from users experimenting with the different ports (Mixing String on top open on sides and vice versa). Looking for a good string for topspin for this racquet." - Gary, Atlanta, GA