The Level 2 widget is displayed by default in Total View when opening a new Stock tab. 

You may enable or disable the Level 2 widget by using the Level 2 button ()

This will display the Level 2 information for the current stock.

The panel offers up-to-date data on the quotes provided by market makers, displaying both the buying and selling prices of a particular stock. Above the Level II view, you'll find a volume bar that indicates recent trades. The height of the bar corresponds to the size of the trade, indicating the position taken.