Smoother contours throughout the racquet head for less wind resistance and extra racquet speed. ISOMETRIC technology continues to help the world's greatest players achieve global success. Developed over 30 years ago, the ISOMETRIC design increases the sweet spot by 7% . Compared to a conventional round frame, a square-shaped ISOMETRIC racquet generates a larger sweet spot by optimizing the intersection of the main and cross strings. ISOMETRIC delivers greater control without sacrificing power. ISOMETRIC is a Trademark of Yonex CO., LTD. Tested by Yonex