Length
This field specifies the maximum number of characters or bytes accepted by the column. It is enabled only when the Data Type is set to one of these types:
- binary
- char
- nchar
- nvarchar
- sysname
- text
- varbinary
- varchar
If the Data Type is set to a user-defined data type that has a system data type, this field displays the length of the system data type and is disabled. Also, to use the SQL Server MAX data length, you can specify -1 in this field.