The ornamental design for an electronicattachment for a wristwatch, as shown and described.
FIG. 1 is a perspective view of an electronic attachment for a wristwatch showing my new design;
FIG. 2 is a side elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a bottom perspective view drawn to a reduced scale; and,
FIG. 6 is a side elevational view drawn to a reduced scale.
The structural features depicted by broken lines in FIGS. 1 and 3 have been shown for the purpose of illustrating portions of the electronic attachment for a wristwatch that form no part of the claimed design.
The wristwatch depicted by broken lines in FIGS. 5 and 6 has been shown for the purpose of illustrating environment that forms no part of the claimed design.