This electronic Air Flow Indicator not only visually shows the operator if the air flow is correct, but has an additional audible alarm to warn the operator if there is a fall in the air velocity. It is small in size, easy to install into any LEV system. Powered by 4AA batteries offering up to 2 years continuous operation. Supplied with mounting bracket, and 4AA batteries. Key Benefits Indication of system performance from a single LED Acceptable flow rate indicated by green LED Alarm condition indicated by red LED and audible alarm Constant monitoring allows users to be protected at all times No external buttons or switches Simple calibration and setup achieved with a few clicks of the internal switches