The ornamental design for a ceiling mount having an arm holding a monitor, as shown and described.
FIG. 1 is a side elevation view of the ceiling mount having an arm holding a monitor;
FIG. 2 is a side elevation view of said ceiling mount of FIG. 1 with said arm holding the monitor rotated 180°;
FIG. 3 is a side elevation view of said ceiling mount of FIG. 1 with said monitor rotated 90° on said arm relative thereto;
FIG. 4 is a side elevation view of said ceiling mount corresponding to FIG. 3 except that said monitor is rotated 90° on said arm relative thereto; and,
FIG. 5 is a bottom plan view of said ceiling mount with said arm holding said monitor disposed as shown in FIG. 3.
The surgical microscope and the arm assembly holding the surgical microscope shown in broken lines are for illustrative purposes only and form no part of the claimed design.