The curator of the museum tells us that such oval amulet boxes are known as kerima, which means kidney, due to their shape.
Shaped like a duck, this jug was possibly used to serve chang (a cereal-based alcohol). There is a lotus bud finial on the lid and medallions with Kirtimukha and auspicious symbols around the body.
The shape of the amulet box on this necklace is unusual.
Kirtimukha may hold a serpent between his hands, as above, or sprouting vegetation, as often seen on the front panel of crowns, or raining jewels.
The historical buddha is seated on a lotus, calling Earth to witness with his right hand, the other holding an alms bowl. In front of him, there are two arhats.