The Yonex PERCEPT 100 is for intermediate to advanced players who are looking for a flexible racket with precision and feel. Features of the Yonex PERCEPT 100: Isometric TM: Developed over 30 years ago, ISOMETRIC's design increases the sweet spot by 7%.  Compared to a traditional round frame, an ISOMETRIC racquet creates a larger sweet spot by increasing the number of intersecting longitudinal and transverse strings in the hitting area.ISOMETRIC technology   Flexcon System: FOR RACQUET FLEX AND FEEL. A tapered and elongated box-frame shaft is made of Flex Force and Flex Fuse graphite for precise ball control 2G-Namd Flex Force: FOR INCREASED BALL POCKETING. Flex Force Graphite allows the racket to flex and snap back quickly for more spin and faster ball acceleration from the string bed Servo ...