The AFM-92NO air-flow monitor is integrated in a 92 x 92mm protective plastic grill and sheilds fingers from injury. Air-flow monitors provide a simple alternative to indicate positive or negative air flow of fans or blowers. When properly installed and connected in series with an optical (i.e. LED) or audible signaling device, a bi-directional switch will activate an electrical contact if the air flow of the fan falls below 8.2 ft/s, turning the signaling device on or off.