Air diffuser

FIG. 1 is a perspective view of an air diffuser, showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is side elevation view thereof;

FIG. 5 is another side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines in the drawings depict portions of the air diffuser that form no part of the claimed design.