The ornamental design for a downrod, as shown and described.
FIG. 1 is a perspective view from below of a downrod in accordance with my design;
FIG. 2 is a front elevation view of the downrod in accordance with my design, the opposite view being a mirror image of that shown;
FIG. 3 is a side elevation view of the downrod in accordance with my design, the opposite view being a mirror image of that shown;
FIG. 4 is an enlarged perspective view from above of the downrod in accordance with my design;
FIG. 5 is an enlarged front elevation view of the downrod in accordance with my design, the opposite view being a mirror image of that shown;
FIG. 6 is an enlarged side elevation view of the downrod in accordance with my design, the opposite view being a mirror image of that shown;
FIG. 7 is an enlarged bottom plan view of the downrod in accordance with my design; and,
FIG. 8 is an enlarged top plan view of the downrod in accordance with my design.
The broken line showing of the canopy, scrolls, fan blades, motor housing, light fixture, blade irons and finial is included for the purpose of illustrating environmental structure and forms no part of the claimed design.