We claim, the ornamental design for an add on module for telephone, as shown and described.
FIG. 1 is a front perspective view of an add on module for telephone showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is another side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is another side view thereof, in which the add on module for telephone is shown in another position;
FIG. 9 is another side view thereof, in which the add on module for telephone is shown in another position showing the base portion detached, rotated 180 degrees, and reattached to the opposite inclined surface; and,
FIG. 10 is another front view thereof, wherein the add on module for telephone is shown in a telephone environment.
The broken lines illustrating portions of the Add on module for telephone are for environmental purposes only and form no part of the claimed design.