https://trc-images.nl/collection_images/hires/2018/2018.2249a-b.JPG#\\TRC-SERVER\TRCSharedWork\TRC Database\collection%20photographs\2018.2200\2018.2249a-b.JPG#
Pair of orange and black marbled buttons (imitation shell). They each have a self shank and thread groove on the reverse side.