The Li-Ning Blade X 800 badminton racquet (4U/ 84 gms) is a marauder of a badminton racquet concocted with everything superlative. This head-light badminton racquet comes engineered with Li-Ning Swing Weight technology, which ensures smooth weight transfer of the racquet into your shots, making them more offensive and lethal. The badminton racquet features a 6.8mm Hard Flexible Shaft that falls under the 4U weight category and offers a string tension of up to 30 lbs. The racquet’s performance is further enhanced using Accele Tech, Resile Shaft, & HDF Shock Absorption technology. 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. Which racket is better 3U or 4U? Most rackets are weighted around 3U (85-89g) or 4U (80-84g), this is because it’s a good weight balance for players to hit hard without compromising on speed. Typically singles players will use heavier rackets 3U (85-89g).