Super Slim Shaft – The slimmest racquet ever produced by YONEX vastly reduces air resistance whilst providing maximum feel. Energy Boost CAP Plus –Uniquely shaped cap which maximizes shaft performance. The front allows the shaft to flex, while the sides arch-shaped curve stabilizes the racquet face by preventing the shaft from twisting.The AERO + BOX Frame –Combines solid hitting feel and quick swing.Flex: Medium. Frame: HM Graphite. Shaft Composition: HM Graphite/ Namd. Joint: NEW Built-in T-Joint. Length: 10mm longer.Weight / Grip:3U(Avg:88g).Stringing Advice:3U: 21 – 29 lbs.