Backpack

FIG. 1 is a front, top, left side perspective view of a backpack showing my new design;

FIG. 2 is a rear, top, right side perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

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