These are series of mobile radio antennas.  The design requirements for each series were: secure mounting to the car body; easy adjustment in the vertical direction; and quick-fold-over feature for garage parking.
The SG series antennas have been selling well for more than thirty years.
(Photography: (top) SG series; (middle) NNR series; (bottom) Revant series)

Good Design Award of Small and Medium Enterprises 1989 (SG)
Good Design Award 1989 (M)
Good Design Award 1992 (NNR)
Good Design Award 1993 (Revant)
Good Design Award 1994 (Rexant)
Good Design Long Life Design Award 2000 (SG)