A mobile drawer supporting frame with a back and sides is molded of a temperature resistant, impact resistant plastic. Integrally molded drawer guides include drawer seating recesses which cooperate with drawer glides on molded plastic drawers to insure that the drawers are seated against accidental opening during movement of the frame. The molded plastic drawers are stackable, as are molded plastic shelf-trays which also can be supported in the drawer guides. The shelf-trays are invertible to provide either a shelf or a tray, and can be inserted either forwards or backwards in the guides to thereby increase their versatility.