The ornamental design for an armextensiontool, as shown and described.
FIG. 1 is a top, front, right-side perspective view of an arm extension tool in accordance with my new design;
FIG. 2 is a top, front, left-side perspective view of the arm extension tool shown in FIG. 1;
FIG. 3 is a bottom, rear, left-side perspective view of the arm extension tool shown in FIG. 1;
FIG. 4 is a right-side elevational view of the arm extension tool shown in FIG. 1;
FIG. 5 is a left-side elevational view of the arm extension tool shown in FIG. 1;
FIG. 6 is a rear elevational view of the arm extension tool shown in FIG. 1;
FIG. 7 is a front elevational view of the arm extension tool shown in FIG. 1;
FIG. 8 is a top plan view of the arm extension tool shown in FIG. 1; and,
FIG. 9 is a bottom plan view of the arm extension tool shown in FIG. 1.
The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.