Hair Straightener

FIG. 1 is a rear, top, and left side perspective view of a hair straightener, showing my new design;

FIG. 2 is a front, bottom and right side perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is an enlarged top plan view thereof, and,

FIG. 8 is an enlarged bottom plan view thereof.

The broken lines shown in the drawings illustrate portions of the hair straightener that form no part of the claimed design.