LabGard Air NU-543 offers the very best in personnel, product, and environmental protection through the use of airflow probe to monitor and maintain real time airflow and displays airflow speeds on the OLED interface. The ability to choose up to three (3) different access opening heights allows our customers the option to select a larger access opening to improve technician movement and reach; select a smaller access opening to lower your total cost of ownership; or select somewhere in-between to get the best of both heights.