The ornamental design for a wristwatch, as shown and described.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The FIGURE is a front perspective view of a wristwatch showing my new design.
The part of the photograph shown in a coarse dot pattern, along with the broken-line perimeter illustrates a portion of the wristwatch that form no part of the claimed design.