The ornamental design for PWB-rack, as shown and described.
FIG. 1 is a perspective view of a PWB-rack of the present invention, illustrating two positions for a rear aluminum bar for accommodating two different styles of mounting packs, and further illustrating hitch pin clips for securing the aluminum rods for easy assembly;
FIG. 2 is a front elevational view of the invention, illustrating four mounting holes for locating the bracket onto wall studs;
FIG. 3 is a rear elevational view of the invention;
FIG. 4 is a left-side elevational view of the invention, the right-side elevational view being a mirror image thereof;