The ornamental design for a shower belt, as shown and described.
FIG. 1 is a front perspective view of a shower belt showing my new design;
FIG. 2 is a front elevation view thereof; and,
FIG. 3 is a rear elevation view thereof.
The broken lines disclosed on the front and rear of the pockets represent top-stitching.
The broken lines depicted in FIGS. 1-3 of a fastening mechanism such as a clip form no part of the claimed design.
The straps are shown broken away to indicate that no particular length is claimed and any portion shown in between forms no part of the claimed design.