The ornamental design for a belt, as shown and described.
FIG. 1 is an elevational front view of the belt showing my new design;
FIG. 2 is a top elevational view thereof;
FIG. 3 is an enlarged partial cross-sectional view of a portion of FIG. 1;
FIG. 4 is a perspective view showing alternate details; and,
FIG. 5 is an environmental view shown while worn.
The broken line showing of details in FIGS. 1-5 is included for the purpose of showing environmental portions of the belt and forms no part of the claimed design.