The Li-Ning Turbo Charging 70 Boost badminton racquet is built on the Turbo Charging Technology Platform that is designed for aerodynamic efficiency. It features an innovative trapezoidal frame construction that energizes the player with extra strong swing speeds and fast reaction times. It is ideal for quick players with rapid attacks and strong defensive skills. The Li-Ning badminton racquets feature a stiffer shaft and highly elastic head design with rapid repulsion power. The racket is suitable for fast players that are skilled in switching quickly between offense and defense. The Turbo Charging Technology Platform uses a 2-digit numbering system. The first digit determines the grade of the racquet as follows: If the first digit is 1, 2 or 3, the racquet is suitable for beginners. If the first digit is 4, 5 or 6, the racquet is suitable for intermediate players. If the first digit is 7, 8 or 9, the racquet is suitable for advanced players. About Li-Ning: Li-Ning Company Limited is a Chinese sportswear and sports equipment company founded by former Olympic gymnast Li Ning. The company endorses a number of athletes and teams worldwide. Is the racket unstrung? Yes, the Li-Ning Turbo Charging 70 Boost Badminton Racket (Purple) is an unstrung badminton racket.