Compelling sound on minimum current Mulit-functional mounting method High reliability and exceptional long life Operates on 3V DC - 28V DC Includes Nut The Piezo Alert is an advanced electronic audible signal device that emits a compelling sound with minimum current draw. This solid state device operates from as little as 3VDC to as much as 28VDC and is rated at 20mA. Sound output is proportional to input voltages and ranges from a minimum of 68dB to over 100dB at 28VDC at 1 ft. The piezo electronic contact points give it high reliability and an exceptional long life. The piezo alert signal operates in free air only. It is not compatible with under water applications. The recommended operating range is from -13°F to 158°F (-25°C to 70°C). This UL recognized Piezo alert is available in two models: PAL-328N and PAL-328. Both models have a black finish.