FIG. 1 is a front view of my new and ornamental design for a wristwatch;
FIG. 2 is a rear view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a fragmentary top view of the wristwatch shown with a portion of the strap removed for ease of illustration;
FIG. 6 is a bottom view of the wristwatch shown without the strap for clarity of illustration; and,
FIG. 7 is a front and right side perspective view of the wristwatch.