Airflow Direction Incorporated’s BALL-IN-THE WALL & BAULIN-TUBE® indicator shows if your room is under proper negative or positive pressure. The ball rolls in the direction of airflow and incorporates a built-in failsafe feature.

Whether the assignment is pre-construction planning, general contracting or building maintenance, reliability is always our standard. T: 631-420-0400 : www.pmconstructionservices.net