The ornamental design for a side packbag, as shown and described.
FIG. 1 is a top-front-right perspective view of a side pack bag showing my new design;
FIG. 2 is a bottom-rear-left perspective view thereof;
FIG. 3 is a top-rear-right perspective view thereof;
FIG. 4 is a front elevational view thereof;
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a right elevational view thereof;
FIG. 7 is a left elevational view thereof;
FIG. 8 is a top plan view thereof;
FIG. 9 is a bottom plan view thereof;
FIG. 10 is a top-rear-right perspective view thereof, wherein the side pack bag has been mounted to an exemplary mannequin; and,
FIG. 11 is a bottom-rear-left perspective view thereof, wherein the side pack bag has been mounted to an exemplary mannequin.
The broken lines showing a mannequin depict environmental subject matter that forms no part of the claimed design. All other broken lines depict portions of the side pack bag that form no part of the claimed design.