Wikipedia
Knottekistje
A knottekistje or wedding casket is a small Frisian money casket.
Apart from their content Knottekistjes are also valuable since in most cases they are made of silver. The boxes are rectangular with a semicircular lid and stand on ball feet. Frisian marriage caskets are delicately engraved with symbolic scenes about love and marriage, often accompanied by a proverb or motto.