The ornamental design for the clip on device for locking touch tone telephones, as shown and described.
FIG. 1 is a partial perspective view of the front, right side and top of
the clip on device for locking touch tone telephones, with the back of a
telephone receiver shown in dash lines for purposes of illustration
including one position where said device may be mounted on a telephone;
FIG. 2 is a left side view of the clip on device shown in FIG. 1;
FIG. 3 is a bottom plan view of the clip on device shown in FIG. 1;
FIG. 4 is a top plan view of the clip on device shown in FIG. 1; and
FIG. 5 is a perspective view of the left side and bottom of the clip on
device shown in FIG. 1.