System Sensor D4120 Duct Smoke Detector, 120V AC 24V AC DC Volt, Sound Alert, Duct Mount, 5 in Overall Ht 7715T797 UL Listed Operating Speed 200 UL Listed Operating Speed 200 RPM Hz 120V 60 50 % AC Voltage Measurement Resolution Not Applicable Dustproof No Basic AC Voltage Accuracy 45 Hz to 500 Hz:1 The SYSTEM SENSOR D4120 is a Photoelectric Contact @ 30VDC 10 A Standby State (mA) Max 25mA @24V DC Max 55mA RMS @24V AC Max 20mA RMS @120V AC Air Velocity (FPM) 100 to 4000 fpm Alarm State (mA) Max 60mA @24V DC Max 130mA RMS @24V AC Max 35mA RMS @120V AC Type Universal Compatible With Air Handling Systems Products By Industry Electrical Minimum Operating Temperature 4 Degrees F Detects Smoke Humidity Operating Range 0% to 95% RH Shape Rectangular AC Contact Rating 10 A @ 250V Voltage Rating 120V AC