Vintage Tone Vigeland solid silver modernist hoop drop clip earrings

A vintage pair of solid silver modernist hoop drop clip earrings - each earring consisting of a concave open flat hoop suspended below a round dot with clip back fittings - marked for Tone Vigeland of Plus Studios for Norway Designs - total weight 23.7grms - overall dimensions 57 x 32mm - c.1960 Norway