The ornamental design for a headset, as shown and described.
FIG. 1 is a top, front, left side perspective view of a headset;
FIG. 2 is a left side view of the headset of FIG. 1;
FIG. 3 is a front view of the headset of FIG. 1;
FIG. 4 is a right side view of the headset of FIG. 1;
FIG. 5 is a rear view of the headset of FIG. 1;
FIG. 6 is a top view of the headset of FIG. 1;
FIG. 7 is a bottom view of the headset of FIG. 1; and,
FIG. 8 is a top, rear, right side perspective view of the headset of FIG. 1 shown in an environment of use.
The broken lines shown in FIGS. 1-5 and 7 illustrate portions of the headset that form no part of the claimed design. The broken lines illustrating the head and neck in FIG. 8 are environment, while the remaining broken lines in FIG. 8 illustrate portions of the headset that form no part of the claimed design.