Contents The Programming Tab » About the ZOS-API » ISystemData TheSystemData » ISDUnitsData Units » ZemaxUnitPrefix SourceUnitPrefixPrint page ZemaxUnitPrefix SourceUnitPrefix Provides the prefix attached to 'Source Units' when printed as text. Next: ZemaxSourceUnits SourceUnits « ZemaxSystemUnits LensUnitsZemaxSourceUnits SourceUnits »