Phone Extension Ringer, Finish Gray, Vertical Mounting, Alarm Current 0.24 amps, Peak Output (dBA) 100 dBA @ 10 ft, Depth (In.) 4 3/4 in, Height (In.) 5 1/8 in, Length (In.) 4 7/8 in, Width (In.) -, Duct Opening N//A, Ambient Temp. Limits (F) -40 Degrees C to 85 Degrees C, Alarm State (mA) 210 mA, Amps AC 0.24 A, Humidity Range ( Percent RH) 0-85 Percent RH, Voltage 120, For Use With Analog Phones