An electrical connector configured to retain an electrical terminal including a terminal lock nib that projects inward into a terminal cavity from a first cavity wall for retaining the electrical terminal in the connector body and a flexible cantilever beam that projects axially into the terminal cavity from a fixed end of the cantilever beam. The coil unit 10 has a drum-shaped core 11 in which a coil form part around which a coil wire is wound is arranged between flange parts 13 and 14 and a lead frame 12 bondingly fixed to the lower flange part 14. The optical box combines the dropping and splicing of optical fibers in a single optical box.