Etrog is a lemon-like fruit in the bouquet of four plants for Sukkot holiday. The Etrog is only kosher for ritual use when its tip is intact, so it must be stored very carefully, cautiously. The container can be anything. Elhanan Jidels donated the ceremonial cup made much earlier to the Chevra Kadisha of Pest in 1819, which could have likely be used as an Etrog container.