Injection-molded product with permeability

A device for enclosing components of a portable electronic device, comprising:

• a first case and a second case,
• wherein each of the first and second cases includes:
• a pattern structure formed on an inner surface of the respective case, and having protruding portions and recessed portions forming a pattern visible on an outer surface of the respective case;
• and
• a coupling structure formed on one or more protruding portions of the pattern structure and extending substantially perpendicular from an adjoining surface of the pattern structure, said coupling structure extending along said one or more protruding portions of the adjoining surface of the pattern structure via an injection molding process without covering any recessed portions of the pattern structure, wherein the coupling structure having a width and a length that is less than a width and a length of the adjoining surface of the pattern structure, and wherein the coupling structure is formed within an area defined by adjoining surface of the pattern structure along the inner surface of the injection molded product to block visibility of, the coupling structure from the outer surface of the injection-molded product;
• and
• wherein the first case and the second case interlocks to each other via the respective coupling structures.