Ensures a stronger, more flexible frame, while the increased flex of the shaft creates maximum power. ISOMETRICTM technology continues to help the world's greatest players achieve success mondial. Developed over 30 years ago, the ISOMETRICTM design increases the sweet spot by 7%*. Compared to a traditional round frame, an ISOMETRICTM square shaped racquet generates a wider sweet spot by optimizing the intersection of the main and cross strings. ISOMETRICTM offers better control without sacrificing power. ISOMETRICTM is a registered trademark of Yonex CO., LTD. *Tested by Yonex By applying counterbalance theory, weight is distributed to the tip of the grip, the top of the frame and the joint for maximum control. The transition to the next shot can be made smoothly, with a succession rapide.