The ornamental design of an airmanifold, as shown and described.
FIG. 1 is a perspective view of the invention.
FIG. 2 is a side elevational view of the invention.
FIG. 3 is a top plan view of the invention; and,
FIG. 4 is a bottom plan view of the invention.
The invention is generally circular and symmetrical, and thus a single side view is representative of the view from all sides. The broken lines represent portions of the article and form no part of the claimed design.