The ArcSaber Series of racquets utilise Yonexs exclusive Cup-Stack Carbon Nanotube technology to create a revolutionary blend of power and control. Positioned at the sides of the racquet frame, this revolutionary technology absorbs and harnesses energy from the shuttle impact to provide the player with unparalleled feel during every shot. This energy is then transferred into a return of supreme strength and pinpoint accuracy. ArcSaber 8DX is specially designed to be strung to HIGH TENSION: 22-27lbs (9.5-12.0kg) Comes strung with a full length head cover .