The ornamental design for cervical collar, as shown and described.
FIG. 1 is a perspective view of cervical collar showing our new design;
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;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a perspective view in use.
The shading in the figures show contour, not surface ornamentation. The stippling shading indicates material contrast between the stippling shaded area and the surrounding areas.