There are three models of the Lung plus.
The Sport model allows for the most airflow and is appropriate for those who are exercising or breathing hard. The Sport model now comes in black as well as white!
The Lung plus 1 is the same size as the Sport model, but has smaller holes for less airflow. This is appropriate for those who might be sitting in a hunting stand, ice fishing, watching a hockey game outside, and want to stay warm.
The Junior is a smaller model with about the same amount of airflow as the Lung plus 1.