Duct Detector 2 Wire Surface Mounting Alarm Current 100mA Standby Current (uA) 70 uA Depth (In.) 1 7/8 in Height (In.) 5 7/16 in Length (In.) 7 3/4 in Ambient Temp Limits (F) -4 Degrees to 158 Degrees F Air Velocity (FPM) 100 to 4000 fpm Alarm Aux. Contact @ 30VDC 2 A Humidity Range ( Percent RH) 93 Percent RH Voltage 24V DC Standards CSFM UL ULC