The Yonex VCORE Pro Tennis Racquet Series is endorsed by Stan Wawrinka from Switzerland, Frances Tiafoe from the United States and Hubert Hurkacz from Poland. ISOMETRIC FOR 7% LARGER SWEET SPOT: 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 technology delivers greater control without sacrificing power. Isometric is a trademark of Yonex Co., Ltd. *Tested by Yonex - VIBRATION DAMPENING MESH (VDM): Vibration Dampening Mesh (VDM) is now used in four of our racquet series. VDM is a stretchy mesh material that is wrapped around the graphite within the grip to filter unwanted vibrations and improve touch and precision. - FLEXCON SYSTEM FOR RACQUET FLEX AND FEEL: A tapered and elongated box-frame shaft is composed of Flex Force and Flex Fuse graphite for precise control of the ball. - FLEX FUSE FOR A SOFTER FEELING: A shock-absorbing polymer is integrated within the graphite’s resin for increased racquet flex and a softer, more plush feeling. - 2G-NAMD FLEX FORCE FOR INCREASED BALL-POCKETING: Flex Force graphite allows the racquet to quickly flex and snap back for greater spin and faster ball acceleration off the string bed.