The ornamental design for a hairtowel, as shown and described.
FIG. 1 is a side perspective view of a hair towel shown secured to a person's head;
FIG. 2 is a front elevational view of the hair towel of FIG. 1 shown secured to a person's head;
FIG. 3 is a rear elevational view of the hair towel of FIG. 1 shown secured to a person's head;
FIG. 4 is a left side elevational view of the hair towel of FIG. 1 shown secured to a person's head;
FIG. 5 is a right side elevational view of the hair towel of FIG. 1 shown secured to a person's head;
FIG. 6 is a front elevational view of the hair towel of FIG. 1 shown unfolded and not secured to a person's head; and,
FIG. 7 is a side elevational view of the hair towel of FIG. 1 shown unfolded and not secured to a person's head.
The dash-dot-dash broken line outline of the partial human figure assists in illustrating how the claimed design may appear when in use, but forms no part of the claimed design. The even-length broken lines and the tab outlined by dash-dot-dash broken lines depict features and portions of the hair towel that form no part of the claimed design.