Details on "Configure Unit"
Information about the Configure Unit dialog for configuring the unit of a parameter data type.
In this dialog you can configure the display of parameter values in the Properties window for the active project. The settings made here override the Revit project's default settings for displaying parameter values.
You are here
Revit ribbon ➤ LINEAR tab ➤ Administration: Element Classes and Property Sets ➤ Tab “Element Classes and Property Sets” ➤ Section “Property Sets” ➤ Selection Property Set ➤ Section “Properties” ➤ Column “Data Type” ➤ 
Unit
Drop-down list for selecting the unit for the respective parameter value. Entries marked with Standard: can be selected to reset the unit to the Revit project's original setting.
Symbol
Drop-down list for selecting the unit symbol. If you select the option Without, the values of the respective data type will be displayed in the Properties window without the unit symbol. For identification purposes, square brackets are placed around the unit in the Data Type column of the Element Classes and Property Sets dialog.
Rounding
Use this drop-down list to select a rounding option for the value. You can set the rounding to the nearest whole number or to up to three decimal places. If you select the option Custom, the Increment field becomes active, and you can set the rounding value there.
Increment
In this field, specify an increment for rounding the value. This field is only active if you have selected Custom in the Rounding drop-down list. For example, if you enter 10, values will be rounded up or down in increments of 10 The same applies to increments specified with decimal places, such as 0.0001.