Displays component size only in project units or in both Imperial and metric units when the project and component units differ.
Find
 Ribbon: Home tab 
 Part Insertion panel 
 Toggle Size Display Mode
 Command entry: 
plantsizedisplaymode
You can toggle the display to show only project units or both project and native units where the two differ. In mixed-unit project, the native unit is shown in parentheses, for example, in a mixed-unit Metric project, you would see 100 (4”).