Visual-Only Features
Compare these features with other manufacturer's products !
  • Failsafe feature allows an operational self check everytime you open the door.

  • Trademark Registered BALL-IN-THE-WALL® Technology

  • Indicates the actual directional airflow, as opposed to an absolute differential pressure reading!

  • Simple, Visual, Accurate and Reliable !

  • Visual SELF-CHECK performs each time the door is opened !!!

  • Installs in minutes . . .

  • No electricity or linkages are required!

  • Requires a minimum of 0.01" w.c. for fail-safe feature

  • Lifetime Warranty! 

  • Great item to function as either a stand-alone or as a safety check for existing monitors !

Click here to see VISUAL ONLY monitors!