We claim the ornamental design for a band of a wrist-top instrument, as shown and described.
FIG. 1 is a top, front, side perspective view of a band of a wrist-top instrument showing our new design;
FIG. 2 is a side view thereof;
FIG. 3 is a front view thereof; and,
FIG. 4 is a rear view thereof.
The dot-dash lines shown in FIGS. 1 through 4 define boundaries of the claimed design and form no part thereof. The other broken lines depict portions of a band of a wrist-top instrument which form no part of the claimed design.