Thin plug assemblies and methods for constructing the same are disclosed. The plug assembly can include a plug portion, a cable portion, and an interfacing portion between the plug portion and the cable portion. The plug portion can include several conductive regions each connected to a conductor of the cable portion to form conductor/plug member coupling(s), for example via a plug extension member associated with each conductive region. The plug assembly is constructed such that a diameter of the plug portion, interface portion, and at least part of the cable portion have substantially the same diameter. Ring structures enhance one or more of the conductor/plug member couplings by providing a press or interference fit directly to the coupling(s). Ring structures are constructed to slide axially over at least one conductor and at least one plug member.