The ornamental design for a hairfasteningdevice, as shown and described.
FIG. 1 is a perspective view of the hair fastening device of the present invention.
FIG. 2 is a front view of the hair fastening device of the present invention.
FIG. 3 is a left side view of the hair fastening device of the present invention.
FIG. 4 is a right side view of the hair fastening device of the present invention.
FIG. 5 is a top view of the hair fastening device of the present invention.
FIG. 6 is a bottom view of the hair fastening device of the present invention.
FIG. 7 is a rear view of the hair fastening device of the present invention; and,
FIG. 8 is a perspective view of the hair fastening device of the present invention positioned on the wearer's ponytail.
The broken lines in FIG. 8 showing additional components of a hair fastening device and a person wearing the hair fastening device are for illustrative purposes only and do not form part of the claimed design. The hair fastening device is shown fastened in an assembled position in FIGS. 1 and 8. The hair fastening device is shown in an open position in FIGS. 2 through 7.
The three circular elements shown in broken lines in FIG. 7 are unclaimed structures that do not form part of the claimed design.