Air filter

[0001]FIG. 1 is a top rear/left perspective view of an air filter;

[0002]FIG. 2 is a top plan view thereof;

[0003]FIG. 3 is a bottom plan view thereof;

[0004]FIG. 4 is a front elevation view thereof;

[0005]FIG. 5 is a rear elevation view thereof;

[0006]FIG. 6 is a right side elevation view thereof;

[0007]FIG. 7 is a left side elevation view thereof; and,

[0008]FIG. 8 is a bottom front/right perspective view thereof.

[0009]The dash-dash broken lines shown in the figures are for the purpose of illustrating portions of the air filter and form no part of the claimed design. The dash-dot broken lines represent break lines where the appearance of any portion of the air filter between the break lines forms no part of the claimed design.