The Levelpro ProAlert Series Audible | Visual Alarm is an an excellent choice for applications requiring upset notification. The heavy duty high impact +NEMA 4X housing is suitable for corrosive as well as outdoor environments. When the ProAlert is active the red cover lights up and the 90db audible alarm goes off. The ProAlert is equipped with a toggle switch which allows for silencing of the audible output. The faceplate will remain lite until the upset condition is addressed.