The ornamental design for an accessory for a weighingdevice, as shown.
FIG. 1 is a front perspective view of the accessory for a weighing device, depicted in operative position on the weighing device, which is shown in broken lining;
FIG. 2 is a front perspective view of the FIG. 1 device in isolation;
FIG. 3 is a top plan view of the FIG. 1 device;
FIG. 4 is a bottom plan view of the FIG. 1 device;
FIG. 5 is a front elevation view of the FIG. 1 device; the rear elevation view being identical thereto; and,
FIG. 6 is a left side elevation view, the right side elevation view being identical thereto.