The ornamental design for an pair of eyebrowbars, as shown and described.
FIG. 1 is a top, front, right side perspective view of and pair of eyebrow bars;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines shown are included depicts environmental subject matter only and form no part of the claimed design. The dash-dot-dash broken lines shown in the drawings define various boundaries of the claimed design and form no part of the claimed design.