Coaster Set Pressed Real Butterflies Bamboo Mid Century Vintage 1960s Barware

Mid Century Vintage 1960’s Coaster Set
Bamboo, with pressed real butterflies into the bottoms
I am not sure if bottoms are glass or plexiglass
Wooden caddy
Interior diameter where glass will sit 2 3/4″
Total caddy 6″ x 4″ x 3 3/4″ tall
Stamped “Made in Japan”