Explanation

Box 1: Custom text/string: A masking method, which exposes the first and/or last characters and adds a custom padding string in the middle.
Only show the last four digits of the values in a column named SuspensionSprings.
Box 2: Default
Default uses a zero value for numeric data types (bigint, bit, decimal, int, money, numeric, smallint, smallmoney, tinyint, float, real).
Scenario: Only show a zero value for the values in a column named ShockOilWeight.
Scenario:
The company identifies the following data masking requirements for the Race Central data that will be stored in SQL Database:
Only show a zero value for the values in a column named ShockOilWeight.
Only show the last four digits of the values in a column named SuspensionSprings.
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/dynamic-data-masking-overview