Abstract: The present invention relates to an earphone that comprises a speaker, a signal wire, housing, and a sound pressure adjustment mechanism. One end of the signal wire is electrically connected to the speaker. The housing holds the speaker and part of the signal wire; the other end of the signal wire extends outside the housing. The sound pressure adjustment mechanism is installed on the housing and provided with at least one hole; the hole is adjustable and/or may be completely closed.

Abstract: The present invention is a combo-type male and female universal series bus (USB) connector which is characterized in that either the USB metallic shell or the electrically connecting terminal board is movable to expose or shield a plurality of electrically connecting terminals attached to the electrically connecting terminal board. When the electrically connecting terminals are completely exposed, the USB connector acts as a male USB connector, and when the electrically connecting terminals are shielded, the USB connector acts as a female USB connector.