Marianne Aav, Rosa Barovier Mentasti and Gordon Bowyer, et al., Tapio Wirkkala - eye, hand and thought, exh. cat., Museum of Art and Design, Helsinki, 2000, p. 371 for a similar example
1970s Precious metal. 3.4 x 6.3 x 5.3 cm (1 3/8 x 2 1/2 x 2 1/8 in.) Serially produced by Kultakeskus Oy, Hämeenlinna, Finland. Marked with Finnish assay mark and purity mark 750. Gross weight 30.2 grams.