The ornamental design for a self-defense band, as shown and described.
FIG. 1 is a top perspective view of the self-defense band of the present invention shown as it would appear in a wrapped position when worn about a user's wrist where the user's wrist would be positioned through the center opening of the wrapped band;
FIG. 2 is a top perspective view of the self-defense band shown in an unwrapped position before being worn by a user;
FIG. 3 is a bottom perspective view thereof;
FIG. 4 is a front perspective view thereof;
FIG. 5 is a back perspective view thereof;
FIG. 6 is a left side perspective view thereof; and,