The ornamental design for a flow-through extension pole handle, as shown and described.
FIG. 1 is a perspective view of a flow-through extension pole handle embodying our new design shown with a brush head and extension pole depicted in broken lines;
FIG. 2 is an enlarged perspective view of just the flow-through extension pole handle depicted in FIG. 1;
FIG. 3 is a side elevation view of the flow-through extension pole handle as depicted in FIG. 2, with the opposite side elevation view being a mirror image thereof;
FIG. 4 is a side elevation view of the flow-through extension pole handle, with the handle portion being rotated ninety degrees relative to the view depicted in FIG. 3;
FIG. 5 is a side elevation view of the flow-through extension pole handle opposite that depicted in FIG. 4; and,
FIG. 6 is a proximal end elevation view of the flow-through extension pole handle as depicted in FIGS. 2-5.
The broken lines showing the valve mechanism, the proximal hose connection, the brush head, and the portion of the extension pole below the handle are for environmental purposes only and form no part of the claimed design.