The ornamental design for an adjustable lock box, as shown and described.
Description:
FIG. 1 is a perspective view of an adjustable lock box in accordance with my design showing the front and top thereof with the top in a partially open position;
FIG. 2 is a rear elevation of the lock box of FIG. 1;
FIG. 3 is a bottom plan view of the lock box of FIGS. 1 and 2;
FIG. 4 is a right end elevation of the lock box of FIGS. 1-3; and,
FIG. 5 is a left end elevation of the lock box of FIGS. 1-4.