http://hl7.org/fhir/StructureDefinition/Distance|4.0.1

Base StructureDefinition for Distance Type: A length - a value with a unit that is a physical distance.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Quantity
typehttp://hl7.org/fhir/StructureDefinition/Distance
Distance.binding.valueSethttp://hl7.org/fhir/ValueSet/distance-units