FIG. 1 is a perspective view of a design element of a holster for a gun in accordance with my new design;

FIG. 2 is a another perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a top view thereof

FIG. 5 is a rear view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a right side view thereof; and,

FIG. 8 is left side view thereof.

The broken lines immediately adjacent the shaded areas represent the bounds of the claim, and all other broken lines are for illustrative purposes only. None of the broken lines form a part of the claimed design.