FIG. 1 is a front elevational view of the separable tool box unit for the bed of a pickup truck showing my new design;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a left side elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a perspective view thereof in separated condition in position of use in the bed of a pickup truck which is shown in broken lines for illustrative purposes only and forms no part of the claimed design.