Use of _total in instance of Alert creation for Percent log counter

Hello All,

I want to create a alert for transaction log alert if percent log space used is more than 80% on all databases using the SQL Server alert.

I have selected the following things while creating the alert

Type: SQL Server performance alert condition

Object: Databases

Counter: Percent log used

Instance: _Total.

I hope selecting _Total in the instance I will get the alert for each database. Otherwise I need to select each database and have to create alert for each database.

Please help me know the use of _Total in the instance.