High-Modulus Graphite The frame is made with high-quality graphite that strengthens and stabilizes the racket. It gives the racket a solid feel as well as enhances its attacking power. IPN Graphite IPN graphite is the culmination of continuous improvement process in graphite technology. It adds extra stiffness and roughness to the frame, thereby increasing the strength and durability of the racket. Isometric Head ShapeEqualizes the length of the main and cross strings in the stringbed, enlarging the sweet-spot for more forgiveness and accuracy on off-center hits.