Possible enumeration values:
| Name | Value | Description | 
|---|---|---|
| None | 
                     0  | 
                
                     Not specified  | 
            
| US | 
                     1  | 
                
                     US units (miles, gallons, etc.)  | 
            
| Metric | 
                     2  | 
                
                     Metric units (kilometers, liters, etc.)  |