The ornamental design(s) for a hairbrush, as shown and described.
FIG. 1 is a perspective view of the hair brush in accordance with the principles of the present disclosure with the first and second members in an approximated condition;
FIG. 2 is a perspective view of the hair brush with the first and second members in an open condition;
FIG. 3 is a right side elevation view of the hair brush of FIG. 1, the left side elevation view being a mirror image thereof;
FIG. 4 is a top plan view of the hair brush of FIG. 1;
FIG. 5 is a bottom plan view of the hair brush of FIG. 1;
FIG. 6 is a front axial view of the hair brush of FIG. 1; and,
FIG. 7 is a rear axial view of the hair brush of FIG. 1.
The broken lines shown indicate unclaimed portions of the article and form no part of the claimed design.