The ornamental design for a lid for a backpacksprayer, as shown and described.
FIG. 1 is a back perspective view of a lid for a backpack sprayer showing my new design;
FIG. 2 is a back view of the lid for a backpack sprayer of FIG. 1;
FIG. 3 is a top view of the lid for a backpack sprayer of FIG. 1;
FIG. 4 is a front view of the lid for a backpack sprayer of FIG. 1;
FIG. 5 is a right side view of the lid for a backpack sprayer of FIG. 1;
FIG. 6 is a left side view of the lid for a backpack sprayer of FIG. 1; and,
FIG. 7 is a front perspective view of the lid for a backpack sprayer of FIG. 1.
The broken lines shown in the drawing are for illustrative purposes only and form no part of the claimed design. The unshown portion of the lid forms no part of the claimed design.