ZI standard mark for silver objects which are submitted in finished condition. (925 fineness).
KN+EB in a hexagon, the importer's mark of
Kempen
Begeer & Vos,
Koninklijke
Nederlandse
Edelmetaalbedrijven, registered in The Hague and Rotterdam, use 1953-1983
Peter.
Source; WaarborgHolland, ˜Netherlands' Responsibility Marks since 1797