a. The hitting surface, defined as the main area of the stringing pattern bordered by the points of entry of the strings into the frame or points of contact of the strings with the frame, whichever is the smaller, shall be flat and consist of a pattern of crossed strings connected to a frame and alternately interlaced or bonded where they cross. The stringing pattern must be generally uniform and, in particular, not less dense in the centre than in any other area.
The racket shall be designed and strung such that the playing characteristics are identical on both faces. The racket shall be free of attached objects, protrusions and devices other than those utilised solely and specifically to limit or prevent wear and tear or vibration or, for the frame only, to distribute weight. These objects, protrusions and devices must be reasonable in size and placement for such purposes.
b. The frame of the racket shall not exceed 29.0 inches (73.7 cm) in overall length, including the handle. The frame of the racket shall not exceed 12.5 inches (31.7 cm) in overall width. The hitting surface shall not exceed 15.5 inches (39.4 cm) in overall length, and 11.5 inches (29.2 cm) in overall width.
c. The frame, including the handle, and the strings, shall be free of any device which makes it possible to change materially the shape of the racket, or to change the weight distribution in the direction of the longitudinal axis of the racket which would alter the swing moment of inertia, or to change deliberately any physical property which may affect the performance of the racket during the playing of a point. No energy source that in any way changes or affects the playing characteristics of a racket may be built into or attached to a racket.