The ornamental design for a hairbrush, as shown and described.
FIG. 1 is a top plan view of my new design for a hair brush.
FIG. 2 is a bottom plan view of FIG. 1.
FIG. 3 is right side elevation view of FIG. 1, the left side being a mirror image.
FIG. 4 is a front elevation view of FIG. 1.
FIG. 5 is a rear elevation view of FIG. 1.
FIG. 6 top perspective view of FIG. 1; and,
FIG. 7 is a close up view of the bristle clusters on the segment labeled in FIG. 6.
The bristles are partially shown for ease of illustration in FIGS. 1-6, with the understanding that each of the somewhat uniformly spaced tufts appears as shown in FIG. 7.