The ornamental design for the multi-function wrench for a powertool, as shown and described.
FIG. 1 is a front upper right perspective view of the multi-function wrench for a power tool;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a top view thereof.
Elements shown in the drawings in broken or phantom lines form no part of the claimed design, and merely illustrate the environment in which the article embodying the design is used.