http://hl7.org/fhir/StructureDefinition/extension-quantity-translation|5.2.0

An alternative representation of the same physical quantity expressed in a different unit from a different unit code system and possibly with a different value.
element_idtypes
Extension
Extension.extension
Extension.url
Extension.value[x]
Extension
Extension.id
Extension.extension
Extension.url
Extension.value[x]